Monkeys are the product of genetic engineering and experimentation by the Von Braun's scientists, augmented by the presence of Annelid parasites. Their latent psionic abilities have been brought to fruition both by the experiments performeed on them and by the Many's influence; as such, they are capable of attacking with Cryokinetic blasts with a moderate area-of-effect. Monkeys are first found in the Medical section of MedSci deck, and are infrequently seen until around Operations.
Note that there is another variant of the Monkey, the Red Monkey, which replaces the regular Monkey in the latter half of the game. Please see its page for more details.
Attributes: Low Hit Points, medium damage, low attack speed, medium movement speed
Weaknesses: Anti-Personnel Bullets and Shells, incendiary damage
Common Loot: Monkey Brain, Chips
Strategy: Monkeys are one of the major pests throughout the game, though their diminutive stature actually hides the fact that they can be quite dangerous in certain situations. While rarely a problem when engaged in close quarters or caught alone due to their low melee damage, when in groups and given enough distance to use their Cryokinesis, they can do a lot more damage. Though it's not worth spending ammo to take them out, you'll be cursing all the while as you try to bash them in melee combat.