This article has not been given a name, as such, the name Amphibian, is purely conjectural.
Minions (left) and the Amphibian (right)
The prehistoric Amphibian creature is a minor character that appeared in the beginning of the film Minions.
As the beginning credits cartoon was playing, it can be seen that the Minions followed a series of creatures as their boss. The amphibian was the last seen creature that they followed in the ocean, and it had just evolved from a form of fish.
The amphibian was the first vertebrate to crawl onto land, with the minions following its path onto land. But as it was crawling on land, it was then crushed (possibly dead) by a Tyrannosaurus Rex.