Drip Lizard

From Wikitroid, the Metroid wiki

The Drip Lizard is an enemy that walks on the ceiling and tries to attack Samus by drooling on her. They are found in two places in Metroid Fusion:

1. The "secret" area behind the sub-zero chamber.
2. The area in Sector 1 where you battle Ridley-X.

The Drip Lizards prior to Ridley-X will transform into Golden Pirates once a pair has been defeated.

The method of locomotion and biological appearance of the Drip Lizard may be an homage to the "Alien" series of films.

They seem to have some link to the Space Pirates, as they first appear alongside the debut of Ki-Hunters and the return of Zebesians prior to the Yakuza battle. Additionally, they transform into Golden Pirates near Ridley-X, which bear a strong resemblance to the Silver Space Pirates that guarded Ridley in Super Metroid.

It should be noted that these creatures do not actually have an official name. Sprite-sheet sites often conjecturally name them "Wormwarts".