#020 Unova / #514 National
Species classification: Ember Pokemon
Ability: Gluttony – Eats held berry when 50% HP remains instead of 25%
Dream World ability: Blaze – Increases power of Fire-type moves by 1.5 if Pokemon has less than 1/3 HP remaining
Location found (Black/White): Evolve Pansear
Egg groups: Ground
Gender ratio: 87.5% male, 12.5% female
Experience at lvl 100: 1,000,000
Base stats: 75 HP / 98 Atk / 63 Def / 98 SAtk / 63 SDef / 101 Spd / 498 Total
Effort values: 2 Speed
Evolution family: Pansear > Simisear via Fire Stone
Hold off until at least level 23 to evolve Pansear, since it learns the new Fire-type move Flame Burst at level 22, which damages nearby opponents in addition to the target and has a solid base power of 70. It also learns Fire Blast at level 34, which is a powerful Fire-type attack (base power 120) that has a chance of inflicting a burn, which is also available as TM38, so you don't have to worry about waiting to level up on that one. There's a handful of other good STAB TM options for Simisear as well, including TM11 (Sunny Day) which boosts the power of Fire-type moves, and TM59 (Incinerate) which does damage and destroys the opponent's berry.
Like the other monkeys, his defense and special defense are both pretty dismal, so it's a good idea to avoid opponents who have a type advantage.
General notes on the elemental monkeys:
They're somewhat similiar to the Eeveelutions of Red/Blue, except that they don't have a Normal-type base form and there are only three types, with one evolution each.
It might be easier to think of them as counterparts to the starters, since depending on the starter you picked, an NPC east of Striation City (in the area where you first encounter Munna) will give you the monkey that's weak to your starter. All three monkeys have these facts in common:
1) They all have the same base stats.
2) None of their evolutions learn any moves through level up, so evolve wisely.
3) They can all learn the new Flying-type move Acrobat at level 31 (first stage only), which does light damage but can hit any of the three opponents in a triple battle no matter where the user is positioned, and does double damage if the user isn't holding an item.
4) The trio's design is partially based on the three wise monkeys: see no evil (Panpour), hear no evil (Pansear) and speak no evil (Pansage).