A type of protozoan-like organism could be found behind transparent membranes within the Impact Crater on Tallon IV, swimming in some type of liquid. Like fish, these creatures cannot be scanned, but can be observed to have a strong heat signature when viewed through the Thermal Visor. Also like fish, they will scatter if shot at, but cannot be harmed on account of the rigid membrane that encases them. Their orange color is most likely caused by the special kind of Phazon found in the Impact Crater.

Similar-looking cell-like organisms can be observed floating behind transparent membranes within all three Leviathans explored during the events of Metroid Prime 3: Corruption, although these entities are blue instead of orange and never react to Samus's presence in any way. They have the ability to vanish and reappear in a set pattern.

Concept Gallery art refers to "glowing protozoans" as features in the Impact Crater's environment.