Petersburg Animation Studio

Background
Petersburg Animation Studio is a Saint Petersburg-based Russian studio founded on March 31st, 2003 by Ilya Popov and Anatoly Prokhorov. The studio is mostly famous for their Kikoriki animated series which eventually became successful and spanned a cult following.

1st Logo (December 22, 2003)
Visuals: Superimposed in the credits of the show is the word "петербург"; above it is a small text "студия компьютерной анимации" ("computer animation studio"), with the first two words and the last (third) word being located between the upper part of the letter "б". The whole text has a white outline, and it's placed under the Kikoriki emblem of the time, which consisted of a simple daisy wheel on a blue rounded square.

Trivia: The emblem in this logo was also used as a screen bug on the original prints of episodes up until episode 110 (The Right To Be Lonely), which is the first episode to not include the emblem as an on-screen bug.

Technique: None.

Audio: The closing theme of the episode.

Availability: It only appeared on the original print of the Kikoriki episode "Past Year's Tale", which was uploaded on Kikoriki's official website before the series' first episodes were aired in 2004 (even though the production of the first episode (The Bench) ended in autumn of 2003), making it the first officially released episode, which also aired on STS on December 30th, 2003.

2nd Logo (May 17, 2004-December 22, 2013)
Visuals: On a white rectangle, there is a square which contains a white spiral P. Next to the spiral P is "СТУДИЯ КОМПЬЮТЕРНОЙ АНИМАЦИИ" (the last two words are stacked)" (2004-2008)/"СТУДИЯ АНИМАЦИИ" (2008-2013). "ПЕТЕРБУРГ" is seen below the text.

Variants:
 * In the original 2004-2012 run of Kikoriki, the logo was placed under the Kikoriki emblem of the time, just like the previous logo.
 * Original prints of earlier episodes of Kikoriki up until episode 40 (A Story for Rosa) had the logo placed over the credits' background. Episodes starting with episode 41 (Little Big Sea) and post-2008 widescreen DVD prints use the regular black background instead.
 * However, weirdly enough, early TV prints of episode 59 (The Chill) also had the logos placed over the background.
 * On some episodes, a credit for Classica-Film (a company that was once responsible for the digital-to-film movie transferring) is seen.

Technique: None.

Audio: The closing theme of the episode.

Availability: Seen on Kikoriki, Kikoriki: New Adventures and the first two seasons of Kikoriki: Pin-Code.

3rd Logo (December 22, 2011, October 20, 2017)
Visuals: On a black background, the spiral P from the previous logo forms. A square fades in behind it, and the spiral P moves away as several glowing lines appear to form the text "СТУДИЯ АНИМАЦИИ " and "ПЕТЕРБУРГ " from the previous logo.

Variant: An English variant exists.

Technique: 2D computer animation.

Audio: The opening theme to the movie.

Availability: Only seen on Kikoriki: Team Invincible. The English variant is seen on Shout! Factory prints of the aforementioned movie.

4th Logo (January 25, 2015-)
Visuals: On a black background, we see several small rainbow rays emerging and rotating. After 2 seconds, they fade out, to reveal that it's actually a rotating, rainbow diamond-like sphere. The diamond-like sphere eventually stops rotating at its angle which resembles a lion face as the white circle grows behind it. Under the diamond-like sphere, the word "PETERSBURG", along with the text "animation studio" under it, fades in.

Technique: CGI.

Audio: A dramatic synth theme, followed by a sound of the tube blowing when the white circle grows in.

Availability: It initially debuted as an in-credit logo on episodes of Kikoriki: Pin-Code, and it was later seen on the studio's current projects like the Kikoriki: Legend of the Golden Dragon movie.