Pteranoid

Pteranoid (プテラノイド) is a sub-boss from Mega Man X5 that appears in Mattrex's stage if the player takes the upper path instead of using the Ride Armor below the lava. It's a Pteranodon robot that releases fireballs from the mouth and follows the player through an area with lava. The fire ball that released by the Pteranoid can be destroyed by either X's buster or the Z Saber.

Its weakness is X's Goo Shaver and Zero's F-Splasher.

Trivia
It acts similar to the Mecha Dragon from Mega Man 2.