United Plankton Pictures, Inc.

Background
United Plankton Pictures, Inc. is a former vanity card of Stephen Hillenburg, the creator of SpongeBob SquarePants. In 1998, Hillenburg formed United Plankton Pictures Inc., a television and film production company, but never used an actual logo until the first SpongeBob episode, "Help Wanted".

1st Logo (1997)
Logo: On a white background, we see a picture of SpongeBob drawn in the same style as the Plankton creatures in the next logo (and similar to that of the SpongeBob drawing seen on the show's title card), over a sand colored background with swirls in rows covering it. On top of him are the hand-drawn words "CREATED BY" in black and underneath is "STEPHEN HILLENBURG" in the same color and font.

Trivia: The words in the logo were used as a copyright disclaimer for the company itself.

Technique: None.

Music/Sounds: The end theme of the pilot.

Availability: Near extinction. Only found on the original cut of the SpongeBob pilot, produced in 1997. This version never aired, and was only released to Nickelodeon employees on a VHS entitled "The Best of Nicktoons 1998". Copies of this original edit circulate online.

2nd Logo (May 1, 1999-)
Logo: On a moving ocean background with a reflection of light, we see some crudely drawn sea creatures, one of them being a less detailed drawing of the character Plankton, holding hands. The words "United Plankton" are above, with "Pictures inc." below, both written in the SpongeBob font.

Trivia:
 * In the SpongeBob episode "Plankton's Army", Plankton's relatives visit the Chum Bucket and he enlists their help into taking over the Krusty Krab to steal the Krabby Patty formula. They return in the episode "Something Narwhal This Way Comes", helping Plankton get rid of the narwhals. They are based on the characters in this logo.
 * The water background used in this logo is also seen as part of the SpongeBob SquarePants theme song, namely the line "Then drop off the deck and flop like a fish!".

Variants:
 * Starting in 2012 with the special "It's a SpongeBob Christmas!", and later with the episode "Extreme Spots/Squirrel Record", the logo is slightly redone for HD-produced episodes. The ocean background now has a greenish tint and there are two more creatures, in addition to them being drawn more smoothly, and starting in 2015 with the episode "Lost in Bikini Bottom/Tutor Sauce", the logo is more zoomed out and the creatures are smaller and further away from the camera.
 * From Nickelodeon's rebrand from 2009 until sometime in 2010, sometimes it will have a copyright notice (as recycled from the 2008-2009 Nickelodeon Productions "Lightbulb" logo cheaply added in).
 * On Kamp Koral: SpongeBob's Under Years and The Patrick Star Show, there is an alternative version of the newer widescreen logo, in which there is a comma separating the words "Pictures" and "Inc.".
 * A textless version without any of the creatures exists.

Technique: Live-action footage.

Music/Sounds: The ending theme of SpongeBob SquarePants and Kamp Koral.

Music/Sounds Variants:
 * On split-screen credits airings of SpongeBob on Nickelodeon and Nicktoons from 2000-2014 along with MTV prints of the show, it's the sound of crashing waves and seagulls (the same sounds from the very end of the SpongeBob theme) that continues into the Nickelodeon logo until 2009.
 * On non-split-screen airings of the SpongeBob SquarePants episodes "Texas"/"Walking Small", cows (presumably from the episode's closing theme, which is Junior Brown performing the show's theme) are heard in the background.
 * On early SpongeBob video releases and The Patrick Star Show, it's silent.
 * Early split-screen versions had a foghorn sound.
 * On a November 2012 CBS airing of the SpongeBob SquarePants episode "It's a SpongeBob Christmas!", CBS' generic theme is heard.

Availability: Extremely common. Seen on SpongeBob SquarePants, and its two spin-offs, The Patrick Star Show and Kamp Koral: SpongeBob's Under Years.
 * Strangely, when the episode "Wet Painters"/"Krusty Krab Training Video" aired in 2002, due to an editing error on Nick's part, the Klasky Csupo "Splaat" logo was shown in place of this on airings with split-screen credits.
 * On November 30, 2011, during an airing of the episode "Pest of the West", this was replaced with the Rainbow S.r.l logo. This was fixed in later airings.
 * The final episode to use the original version of the logo was "Hello Bikini Bottom!". The enhanced version was first seen at the end of the episode "It's a SpongeBob Christmas!", as well as all episodes beginning with "Extreme Spots"/"Squirrel Record".
 * The audio variant is extinct, as it was last seen when MTV aired the show in February 2016; instead of using the show's original credits, it used split-screen credits that Nickelodeon used from September 2009 until June 2012. It made surprise re-appearances on a June 2018 Nickelodeon airing of the episode "The Hot Shot", a November 2018 airing of the episode "Truth or Square" and December 2022 airings of the episodes "Truth or Square" and "Atlantis SquarePantis" respectively, as Nickelodeon messed up the three episodes' credits and the split-screen credits template was used.
 * This logo doesn't appear on any of the SpongeBob SquarePants films, as they use an in-credit notice instead.

Legacy: This is a favorite logo among SpongeBob fans.