Splats is a Badnik robot based on a rabbit. This Badnik was originally supposed to appear in the original Sonic the Hedgehog game in 1991, but it was cut from the final game for unknown reasons. Despite its removal from the first game, Splats has appeared in numerous other Sonic-related media over the years. It would make its first canon game appearance in Sonic Mania in 2017.
One of Dr. Eggman's more simplistic Badnik designs, Splats isn't particularly threatening. It resembles a rabbit with a grey body, a pair of short arms, and while it has thighs, it does not have complete legs. On the bottom of its body is a spring which it uses to hop around.
Sonic the Hedgehog (1991)
The Splats was originally intended to appear in Sonic the Hedgehog on the Mega Drive, but was scrapped for unknown reasons. It was to appear in the Green Hill Zone and would behave in a similar manner to the Moto Bug, only it would hop rather than roll. It appeared in the 2013 re-release of Sonic 1 as an object that could be placed in Green Hill in the game's Debug Mode.
Sonic 3D Blast
An unnamed enemy resembling Splats appears in Sonic 3D's Diamond Dust Zone. It appears to be a robotic bunny with spikes on its body that rides a pogo-stick. Like most of the Badniks in Sonic 3D, this foe does not attack the player directly, though the player is required to defeat all enemies in a stage to free the captive Flicky birds within and progress through the stage. This Badnik will simply bounce around over a short radius and can be defeated by any of Sonic's attacks.
Splats makes its first canonical game appearance in Sonic Mania. It is first seen in the Flying Battery Zone amongst several other scrapped Badniks in heaps of junk that appear in different parts of the stage. It appears as an active enemy in the Press Garden Zone and leaps out of giant jars of ink before proceeding to bounce forward, leaving splotches of ink on the ground where they bounce. An infinite number of Splats will emerge one by one from the inkwell so long as the player character isn't standing on top of it.
Sonic the Comic
In the Sonic the Comic series published by Fleetway Editions, the Splats were a part of Dr. Robotnik's Badnik army. Due to the different artists, the Splats were often give a slightly different look between their appearance, though they retained their overall resemblance to their in-game sprites. Splats, along with two Moto Bugs, were the first Badniks ever to face Sonic. They teamed up with several Badniks multiple times to defeat Sonic afterwards, but without success and were eventually rendered obsolete.
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, the Splats was one of Robotnik's Classic Badniks. Though initially used to combat the Knothole Freedom Fighters, the Splats were eventually rendered obsolete by more advanced robots and got decommissioned, the remainder being sent to the Robo Hobo Jungle and the Island of Misfit Badniks.