A mutant who suffers from this mutation has an altered appearance that mimics that of the great apes (such as gorillas and chimpanzees) - shorter legs, quadrupedal, and elongated arms that permit the knuckles to touch the ground and aid in movement.
The character’s shortened legs reduce his base speed to 2/3 normal. However, if all 4 limbs are used to move (arms and legs), his speed is normal. A character using his arms to assist movement cannot be wielding a weapon or carrying items in his hands.