The next entry in the old Rules Cyclopedia is "Baboon, Rock"... also not actually a real animal. However, it's a great occasion of serendipity, since the previous entry detailed apes, and this one gives me the opportunity to stat out their cousins, the monkeys (yes, baboons are a type of monkey!).
There are two broad groups of monkeys: the platyrrhines, or "New World monkeys"; and the catarrhines, or "Old World monkeys." The differences between them are quite distinct (at least in terms of their game stats), but some players and BMs won't care about these distinctions. In high-fantasy campaigns, it shouldn't matter; in more "realistic" campaigns, the two types of monkeys probably occupy different continents, and will have a fierce rivalry with one another.
|A flat-nose monkey|
Most monkeys are prideful, curious, and extremely intelligent. Beyond this, they do not have a recognizable stock personality; their temperaments range from meek to aggressive, dependent on species.
The following game rules reflect the traits common to the "default" monkey. Variations on these stats are found in the individual entries that follow.
AT (Dam.): bite (1d3)
Beginning HP: 3 
Habitat: Tropical to temperate forest, savannah, or woodlands
MV: 6; climb
- Hands: Unlike most other species, monkeys have true hands, very similar to those of longpaws. They a get +2 bonus on all Scout and Trickster lore checks to manipulate fine tools, spring traps, perform "sleight of paw" tricks, and other activities that mimic the use of human hands.
- Low-Light Vision
- +4 bonus on all lore checks that involve climbing, jumping, or swinging from the canopy or similar environments (like the sails and netting of a human ship, for instance).
- -3 penalty on all lore checks involving feats of strength
- Suitable Niches: Guardian, Healer, Herbalist, Runner, Scout, Seer, Trickster.
As their name implies, the down-noses are classified by the shape of their nose: long and thin, with downward-facing nostrils. Their ranks contain some of the most well-known types of monkey, such as the baboon and the macaque.
Down-noses take pride in their long matrilineages, and young males are usually the only troop members who leave to seek adventure (females tend to stay with their mothers, or with their mate as part of a "harem"). A typical down-nose community will feature a large female population with one or a handful of males who have multiple mates. In their own eyes, this makes them more enlightened than their prudish flat-nose cousins.
|A baboon, one of the most famous of the down-noses.|
Among the most distinctive of the down-nose monkeys is the baboon, often mistaken for a type of ape by non-monkeys and non-apes. However, it is unwise to make this comparison to the face of a baboon or a true ape; both find it highly insulting.
Baboons possess all the standard monkey traits, except as noted below:
AT (Dam.): bite (1d5 [1d6])
Beginning HP: 5 
- Growth Spurt: At 2nd Total Level, a baboon's size increases from Small to Medium.
- Poor Swimmers: Baboons automatically fail all lore checks that involve swimming, unless they have been specifically trained in the skill by a member of another species.
Even then, they suffer a -4 on all lore checks involving swimming.
- -1 penalty on all lore checks involving feats of strength.
The flat noses are easily distinguished by their noses, as well: flatter than those of most other primates, with sideways-facing nostrils. Their numbers also include the smallest monkey species in existence, the pygmy marmoset (always Size Diminutive).
However, what truly sets them apart -- or at least the trait of which they are most proud -- is their prehensile tails. Unlike the catarrhines, flat-noses can use their long tails almost as a fifth limb. They also tend to form monogamous life bonds, which gives them a sense of moral superiority over their down-nose kin.
Flat-noses have all the standard monkey traits, except as noted below.
- Prehensile Tail