The Rhinotank (リノタンク), is a Badnik that appears in Sonic Adventure, Sonic Advance and the Nintendo 3DS version of Sonic Generations. It is a rhinoceros-like Badnik apparently based on the Rhinobot, both in design and purpose. They patrol an area back and forth while idle and charge against a character when they spot them.
Other future Badniks that resemble the Rhinotank are the Rhino Liner from Sonic Heroes and both the Egg Liner and Egg Chaser from Sonic the Hedgehog (2006).
A Rhinotank in Emerald Coast.
The Rhinotank made its debut in Sonic Adventure, where it shows up in Emerald Coast for Sonic and E-102 Gamma.
A Rhinotank in Angel Island Zone.
The Rhinotank made a second appearance in Sonic Advance with the exact same purpose and attacks, though with a different design. They show up in Neo Green Hill Zone and Angel Island Zone.
Sonic Generations (Nintendo 3DS)
The Rhinotank then made a third appearance years later in the Nintendo 3DS version of Sonic Generations, where it is found again in Emerald Coast with their original design from Sonic Adventure.