This information taken from
Bulbapedia. With some added tweeks...
Pichu, the Tiny Mouse Pokemon.
Physiology
Pichu is a small ground-dwelling rodent. Its fur is very short, and it is pale yellow in color. The tips of its large ears are black, and it has additional black markings on its neck and tail. Its tail is short, but still bears some resemblance to the large lightning-bolt structure it will develop later on in life. It has pouches in its cheeks, which are pinkish colored and used for storing electricity. Its nose is extremely small, almost like a dot. It is classified as a quadruped, but many have been known to walk easily on their hind legs. Pichewie tends to enjoy walking on her hind legs more.
Gender differences
Pichu normally have no gender differences.
Special abilities
Pichu, like its evolutions, is capable of producing electrical sparks from its cheeks, charging itself with electricity more easily on days with thunderclouds or when the air is very dry. However, since Pichu is only a baby, it cannot control them as well, and may release electricity unintentionally. However, it is not able to store large amounts of electricity in its body. Pichu, and its evolution family, Pikachu and Raichu, are the only known Pokémon that can learn Volt Tackle.
Behavior
Pichu are social Pokémon known for their playfulness. They tend to be very
mischievous and are always on the lookout for something fun to do. They are usually found in groups, typically with members of their own species, but occasionally with other types of Pokémon. Like their evolutions, they are capable of storing electricity from the atmosphere, however, this ability requires much practice to perfect. Pichu are prone to randomly discharging electricity, as they are not fully mature. They become better at holding power as they grow older. Pichu are frequently observed touching tails with each other, creating a shower of sparks.
Habitat
Pichu primarily live in forests like their evolution, Pikachu, although they have also been depicted to thrive in urban areas. Pichewie, however, tends to appear wherever she wants.
Diet
Pichu appear to be particularly fond of apples. The Spiky-Eared Pichu loves Grepa Berries. However...something is odd about this Pichu. Very odd indeed...
Found under an
TheVendingMachine