The IceBoss is the name of an unused boss creature in Metroid Prime. It was first discovered in an animation video that Derek Bonikowski listed on his website as one of the "Selected animations from the Metroid Prime series of video games". The video was removed from the website for unknown reasons. Its name is derived from the file, "IceBoss_Taunt.MOV". Greg Luzniak conceptual art depicts the creature standing several meters taller than Samus Aran.The IceBoss loosely resembles a furless, blue-skinned primate, with its most distinguishing features being its six limbs (two pairs of arms and two legs), its tusks and the crystals which cover most, if not all, the creature's dorsum along with the back of its arms.
In its only existing animation , the IceBoss exhibits behavior similar to that of a gorilla by standing upright and beating its chest with its first pair of arms while roaring before reverting back to its standing animation, in which it takes a partially flexed posture that seemingly allows its body weight to be pressed against the ground through the second pair of arms' knuckles. Its facial features, however, share greater similarities with those of a baboon's. The name of the video implies that it performs this action to taunt Samus.
Based on the environment featured in the creature's concept art, it is likely that the boss was intended for the Phendrana Drifts. Further evidence supporting this is IceBoss's physical characteristics, such as its crystal formations and blue skin, both which are shared by the majority of bioforms present in the Phendrana Drifts.
- The IceBoss is one of only a few creatures in the Metroid series to be or resemble a mammal.
- The IceBoss resembles a Pokémon named Machamp and Goro from the Mortal Kombat series, in that they have six limbs.
- The IceBoss is also extremely similar to the Wendigo in that both are mammalian predators which live in extremely cold climates and both stand miles taller than a normal human. Both also are a blue-gray colour and both taunt their victims before moving in for the kill.
- The Reptilicus from Metroid Prime 3: Corruption also have six limbs.
- Thardus may have replaced this boss, due to the giant size and setting in a cold climate. Thardus may have been intended as a separate boss from the IceBoss as the Phazon ore monster was originally meant to appear in the Magmoor Caverns.