Grim

The Grim is a new strain of Chimera that appears in Resistance 2. The Grim has the appearance of a naked Hybrid, lacking cooling units. The Grim's main form of attack is to run at the player and melee him/her.

As the Grim lacks cooling packs, and since it runs quite fast, it can be assumed that the Grim is not designed to live for more than a few hours at most. Without the cooling units, these Chimera will overheat and die.