Boomerang

1st ID (April 1, 2000-January 19, 2015)

Visuals: While they all are different, they mostly have a white background and start with the screen switching on with a buzzing effect, and end with a variant of the 2000-2015 Boomerang logo, which is a cornflower blue abstract "B", roughly designed after the right half of the 1959 Hanna-Barbera logo and also an abstract boomerang, with a light yellow outline around the letter and a dark blue drop shadow. Here are all of the bumpers with this style:

Telephone: The camera flies to the right, passing a "The Banana Splits Talking Telephone" toy, following by it passing another going to the left. There's eventually a few more on the left flying away, before a whole row of them is shown passing by. It then cuts to a front view of them, closer than before, when the passes by one in the distance with the receiver off the hooking, and the camera slows, moves to the space, and zooms in on it. The camera then pans to the end of the receiver, revealing sound holes in the shape of the Boomerang logo, in which the screen "switches" to it zooming in by a static effect.
Drum Set: The camera focuses itself on the main drum of the "Fred Flintstone's Bedrock Band" toy, in which the camera zooms out to reveal the whole toy. After 3 shots of it from different angles, the cymbal suddenly becomes the shape of the Boomerang logo. After a final shot with the end of the drum solo, the entire thing fades out barring the cymbal, and then zooms up to take up almost the entire screen, while becoming cornflower blue. The cymbal continues to shake before fading to the logo proper.
Xylophone: The camera is shot over "Yogi Bear & Friends Ding Dong Xylophone" toy, where mallets smack down across it, colored cornflower blue (the real toy's mallets had red on the ends). This is repeated 2 more times, before a shot of the entire thing, including the bell, is shown. The mallets are runned across the keys before performing a long descending series of notes, ending with one of the mallets banging them with the Boomerang logo on it. The xylophone and mallets fade out, leaving the Boomerang logo in its typical styling. It's slightly smaller than usual.
Vari-Vue: Several "Vari-Vue TV" toys appear one by one. The screen slowly zooms out as more and more fill up the screen. The camera then cuts to wider and wider shots, until eventually the entire screen is filled with them barring a single space. They stop moving, and a dark blue TV with the Boomerang logo in it fading through different shades of colors. The camera then zooms on it, and continues until the logo zooms out.
Yo-Yo: A yo-yo drops down from the top and spins rapidly for a little bit, revealing it to be an image of Fred surprised at Dino as a recently-hatched baby dinosaur (a real toy). It then goes back up, which is followed by several more dropping down from the top and doing the same thing. After the last one goes up, a yo-yo with the Boomerang logo on it comes in from the right and spins in a rapid speed before being reeled in a bit. The screen then stalls for a second before the camera jarring zooms into it.
Marionette: The camera starts off by showing a butt "shaking" at the screen. It then shows several Yogi figures crudely "dancing" in the background, while one much closer to the screen moves across them, turning its head to face the screen before going offscreen. It then shows 2 Yogis standing side-by-side a marionette of Huckleberry Hound moving around as the Yogis slide offscreen. The camera then moves up to reveal that the strings are attached to a wooden Boomerang logo that moves about for a bit. The strings then disappear, the logo becomes its familiar color, and then fades the screen.
Target: A "Quick Draw McGraw Moving Target Game" toy comes in from the right, stops for a bit, and moves to the right, as 2 suction cup darts fly in, missing the toy. The toy then peeks in from the right and then moves quickly along, with 3 more darts missing it. The toy then comes in from the left, rears back, and then attempts to evade the next set darts. However, it instead gets struck with a oversized dart, causing it to recoil it back a bit. The camera then zooms in to reveal a small Boomerang logo molded into the end of it.
Handpuppet: Several multi-colored versions of an Astro hand-puppet move in from the screen, bouncing off in opposite directions, and then they start to curl into 2 oblong patterns while they zoom out. Several moving rings of them then zoom through and past the camera before revealing a ton of moving patterns zooming out forming the shape of the Boomerang logo. It then switches to the actual logo by the same static effect from "Telephone".
Push Puppets 1: The camera shows off several "push-button" puppet toys slowly wavering around, and the camera slowly zooms in past them. The Fred Flintstone puppet then becomes stiff and falls over, revealing a sticker of the Boomerang logo on the base, as the camera quickly speeds into it.
Rush Hour: The camera shows off several moving toys moving about in several shots. The 2nd shot has Yogi and Boo Boo's car driving towards the screen, while the next shot has a Huckleberry Hound car toy driving towards the screen as well. In the final shot, they collide with each other as the camera pans over the toys that they form the rough shape of the Boomerang logo, all before they become solid cornflower blue and then does the same static effect to change into the logo.
Yogi Bear: The camera starts off with a close up of a Ranger Rick figure. The camera then slowly backs up to reveal another Ranger Rick figure, and then a statue of Yogi Bear towering over then. The camera then rapidly speeds up to reveal a ton of Ranger Rick figures, before the camera turns up to reveal them forming the Boomerang logo and then ends the same way as "Rush Hour".
Hoppers: A ton of Huckleberry Hound hopper toys leap across the background and foreground. One of them leaves footprints, and then the camera pans over to them, revealing the Boomerang logo.
Cupcake: The camera shows off a The Flintstones lunchbox, in the dark illuminated with a flashlight. It then pans over another The Flintstones one and then stops at a The Chan Clan lunchbox. The camera then shifts upwards to reveal that there's a whole wall of lunchboxes, and then pans over to the right to fly towards a The Funtastic World of Hanna-Barbera lunchbox. The lid is removed to reveal the same lunch box, but opened in the dark, with a dim light source from the right and a cupcake out in the open. The camera then zooms in past the lunchboxes and then has the whole scene in frame. The camera then fades to the cupcake, revealing white icing with the Boomerang logo on it.
Lunchboxes: The camera moves around a large amount of lunchboxes standing upright like walls. As it veers around them, it stops at a opening with a lunchbox in the distance, before quickly moving up to it. It then fades to the top of a Flintstones lunchbox, which opens up, revealing a container in the shape of the Boomerang logo, which then fades to that a second later.
Piggybank: The camera is centered over a large group of Huckleberry Hound piggybanks. It then cuts to a front view of them, in which the one in the middle is removed from view. It then moves around the camera, struggling to shake out a coin. It shakes on the left side, then on the right, then extremely close to the camera by going up and down, and then from the upper right corner, in which it finally launches out a coin shaped like the Boomerang logo. It then bounces up and flips around, becoming the normal logo in a much smaller size. Unlike most of the logos, this doesn't have the switch-on effect at the beginning.
Push Puppets 2: The camera shows an unsteady shot of a Dino push puppet toy on a purple background, which twitches his tail. It then shows more character push puppets on different colored backgrounds, separated by a white grid. They continue to show more and more, until they show a Boomerang push puppet toy on the white background, which springs upwards.
Fred Flintstone: Same as "Yogi Bear", but all the figures are instead Fred Flintstone statues.
Ring Toss: The camera shows off a "Huckleberry Hound Ring Toss Game" toy, 1st with his twin revolvers, and then a shot of his head. It then shows it from a farther view as a ring is thrown and it misses. Another shot of it, and another ring misses. A shot from the top, and 2 more fly around it. A shot closer and it flies off. And then a shot from the top, and a ring shaped like the Boomerang logo flies on his hat. The game disappears, the ring rotates around, and becomes the logo by the same static effect seen in a few of these logos.
Packaging: A Yogi Bear statue moves in from the side in a rythmic style, followed by another close to the screen. It then shows a shot of them in perfectly aligned rows, all moving at the same beat. It then fades to a shot of them from below, followed by another fade to the opposite direction, where they are then covered by white boxes with the Boomerang logo printed on them. It then cuts to a front view of the boxes, before the camera zooms onto the logo and they pass to the right in 2 more beats. This also doesn't have the switch-on effect at the beginning.
Bedtime: The environment is dimmer than usual, only illuminated by several lamps themed after the Hanna-Barbera characters. One switches off, followed by another, and then the rest basically switch off one-by-one until the entire background is black. A white light then appear in the distance, in which the camera zooms up to reveal that it's a Boomerang logo night light.

Technique: A mix of photography, stop-motion, CGI, and live-action. These were done by Primal Screen in Atlanta, who are also known for animating a majority of PBS Kids IDs in the 2000's.

Audio: Once more, all of them are different, but they usually have a static buzz at the beginning. Here's all of them in order:

Telephone: A series of repeating drums and dial-up noises make up the tune in here. There's also the sounds of a phone ringing, Fleagle's laugh (voiced by Paul Winchell), and then the static buzz, ending with 2 more sets of dial-up noises.
Drum Set: A drum solo, fittingly, with Fred's laugh, him saying his "YABBA-DABBA-DOO!" line (voiced by Alan Reed), and after the solo's finished, a different cheeky laugh is heard.
Xylophone: A funky string tune, with the sounds of the xylophone playing as well. A ding is heard when the logo fades in.
Vari-Vue: An acoustic synth wave.
Yo-Yo: A drum beat plays through out, with a whirring sound for the 1st yo-yo, followed by the sounds of Dino's yips, and then another whirring sound for the Boomerang yo-yo, and then a "biting" sound when it zooms in.
Marionette: Bongos and "bonks" can be heard throughout, along with a "radio" guitar tune.
Target: The sounds of hooves clopping, shots being fired, and a bow sound effect. A western-styled tune plays here as well. A squeak and then another shot fired is then heard at the end.
Handpuppet: A hypnotic-sounding rhythm of synth noises, followed by the static buzz at the end.
Push Puppets 1: Slowed-down noises of wobbling, as well as a clang when the Fred puppet falls and ends with a low-pitched "twang" sound effect.
Rush Hour: A tune made of car beeps and horns, as well as the sounds of colliding, an car alarm going off and then the 2-beep carkey jingle sound.
Yogi Bear: A stinger of stock music with Ranger Rick's lines thrown in (played by Don Messick). It then ends with a "bonk" sound.
Hoppers: The hoppers hopping.
Cupcake: A hiccup at the end
Lunchboxes: a drum tune with the lunchbox opening
Piggybank: The piggybank shaking, with a cash sound effect
Push Puppets 2: The sounds of the puppets twitching.
Fred Flintstone: An odd-sounding remix of The Flintstones theme with "Yabba-Dabba-Doo." being played on repeat.
Ring Toss: The sound of the rings throwing.
Packaging: The music sounds like Jet's "Don't Walk Away".
Bedtime: A dreamy bedtime tune, with several H-B "blink" sounds for the lights turning off, and then a "stretching" noise when zooming into the night light.

Availability: Most were introduced at the network's launch and were replaced when the international rebranding came in early 2015 for the United States. Most others dropped them off after quite a few years, some earlier than others.

Legacy: A classic set of bumpers to those who grew up with either the original cartoons or Boomerang itself, at least in the United States. Most international versions of the channel pre-emptedly dropped them off after a few years.

2nd ID (January 19, 2015-)

Unknown.