Dino-Rhino
From SMWiki
Dino-Rhinos march slowly, following Mario. If they encounter a ground-based obstacle, they will jump over it to get at Mario. If Mario stomps a Dino-Rhino, it will turn into a smaller, more dangerous Dino Torch and instantly begin breathing fire at him. A spin jump will destroy it in one blow and skip this Torch stage. Dino-Rhino cannot be destroyed by fireballs or cape swipes, shells pass through it harmlessly, and it is too big for Yoshi to eat. Mario's slide attack can defeat it on slopes, and a Star can take it out in one hit.
Hacking information
Dino-Rhino is sprite 6E. It uses palette E, and the level should be set to use sprite palette 0 to give it its proper teal color. Its graphics will only look right with the Dino-Rhino tileset. (SP4=23)
There are unused graphics for Dino-Rhino to breathe fire, (perhaps a vertical version of Yoshi's fireballs) but this was not included in the original game. Mikeyk made a custom sprite which allows Dino-Rhino to breathe Dino-Torch's fire, but there is no sprite index with which it will work properly. If any other enemies are on screen with it, they will become invisible until its fire subsides.

