The following material is Open Game Content from the Menace Manual SRD
The statistics below represent a chimpanzee, but they can also be used for any ape or monkey of similar size, such as a howler monkey. Most such animals are omnivorous, although some can be quite fierce and aggressive.
Improved Grab (Ex): To use this ability, the chimpanzee must hit a single opponent that is its own size category or smaller with both slam attacks in the same round. During any round that it grapples such a creature, the chimpanzee may make one additional grapple check as a free action at its highest attack bonus. On a successful hit with such an attack, it automatically deals bite and slam damage to its foe.
Bonus Feat: A chimpanzee gains Weapon Finesse (slam) as a bonus feat.
Skill Bonuses: A chimpanzee gains a +8 species bonus on Climb checks and a +4 species bonus on Jump checks.
Chimpanzee: CR 1/3; Small animal; HD 1d8+1; hp 5; Mas 13; Init +3; Spd 30 ft., climb 20 ft.; Defense 15, touch 14, flatfooted 12 (+1 size, +3 Dex, +1 natural); BAB +0; Grap –2; Atk +3 melee (1d4+2, bite); Full Atk +3 melee (1d4+2, bite) and –1 melee (1d2+1, 2 slams); FS 5 ft. by 5 ft.; Reach 5 ft; SQ improved grab, low-light vision; AL none or trainer; SV Fort +3, Ref +5, Will +2; AP 0; Rep +0; Str 15, Dex 17, Con 13, Int 2, Wis 14, Cha 8.
Skills: Climb +14, Hide +6, Jump +7, Listen +5, Move Silently +6, Spot +5.
Feats: Weapon Finesse (slam).
Advancement: 2–3 HD (Small).