Mystery Creature

Officially known as Mystery Creature, this lizard like being is a new form of Ridley in Metroid: Other M. It appears as a large feathered purple lizard-like creature. Samus sees the creature attacking the 07th Platoon in the Biosphere Test Area from the Exam Center and runs to save them. However, the creature seems to be lying in wait for her and ambushes her. It pins Samus down and attacks her with its tail. The soldiers try to help her, but they are distracted by swarms of enemies including Reos and Griptians. Samus attacks the creature's tail as it attempts to strike her head. Eventually Anthony shoots his plasma weapon at the creature, knocking it off Samus. It then flees. Anthony shoots at it again, but it disappears.

The 07th Platoon finds Lyle Smithsonian's body ripped into shreds. After following a trail of green ooze, she finds a husk of the little white creature, which implies that it molted into this lizard and killed Lyle.

Much later in the game it is found as an empty husk outside the room where Ridley is battled, hinting that it and its previous form are juvenile or adolescent forms of the space pirate. This may be why it immediately tries to attack Samus when she emerges instead of attacking the soldiers, and ambushed her when it could have been fighting the soldiers.