Bendors are a species-caste of for the alien invaders Corridor 7 on Mars. They have the ability to morph into common, everyday objects in order to ambush trespassers or other foes. Considering the idea that the Solrac leading the invasionary force utilizes potent psychic power, if this is considered to be a medium amongst all of the species then Bendors likely do not physical alter shape at all, instead projecting a mental field that causes those around it to perceive it as something else. It may also be a technological devise that they are armed with that allows them to change. Less likely they may be able to physically alter their shape into nearly anything, including chairs, barrels, filing cabinets, and plants. They are extremely loyal to their own kind, and if an opponent kills a Bendor, others in the area generally rush to the scene.
A Bendor most often will remain in this disguised state until an opponent passes by, at which time it will revert to its original shape and being a surprise assault; they prefer to do so from behind, indicating that they are not the most courageous or honorable of organisms. Because a surprise attack is only a surprise for so long, Bendors carry heavy weaponry to inflict as much damage as possible to an opponent as quick as possible. Unfortunately for the Bendor, their morphing procedure emits a telltale sound, and can alert their potential victim(s) to their presence. They also cannot act in any other way in mid-transformation, as all of their energy must go into the change back, assuming that it is in fact a physical trait.
Assuming their transformation is physical and their sharp tusks indicate a mouth full of teeth built for a carnivorous appetite, then this is likely how they hunt prey on their homeworld.