The Crocomire is a large dragon type creature that is only found in Super Metroid.
Although incomplete code suggest that was set to make an appearance in Metroid: Zero mission
It is a miniboss that is located in Norfair
 Super Metroid
The boss makes its only full appearnce in Super Metroid and must be fought to progress Norfair.
Oddly, it's located in a room that's filled with superheated "lower Norfair" magma, and the aim of the boss is to push it into this magma which completely melts its skin off.
Once it falls into this Magma, it's skin graphically melts off and it "swims" to another part of the arena.
As Samus follows the bubbles produced by Crocomore, she is stopped at all wall covered in spikes, the boss theme starts playing in anticipation of another fight, but Crocomire, now as a skeleton bursts through the wall and merely collapses into bone.
An Energy tank can be found by crossing the lava that Crocomire fell into.
Only found by using ROM editors, a sprite that highly resembles a mini Crocomire appears. The sprite's coding is totally complete and is usable in game.