Pinchy, the Large Jaw pokemon, was the very first introduced pokemon in the game. It's pokedex number is 001, and can only be obtained by selecting it as your starter pokemon in a gift from the professor. They currently are not found in the wild, and it is assumed that the one you recieve is the last of it's kind, entrusted to you.
A pinchy's body looks relativly like an ant's, except it has an insanly large head, and eyes. It's main colors are purple and yellow, which purple is the main body, and yellow being the eye color. It has 6 legs, like most other insects, but when it evolves, the front legs become large arms with extended blades at the ends. In return, it's legs grow bigger to support it's body.
Pinchies are mainly found eating Pecha Berries, they find in forests. It is thought that this is because Pecha Berries are known to be a poisinous fruit, that, if eaten when healthy will poisin, but if a pokemon is already poisined, it will be cured, and since pinchy's evolution is dual bug/poisin, it could possibly eat these to build endurance against poisins, so it is ready to evolve. Though Pecha berries consist of 75% of their diet, the rest consists of eating other various bugs, such as Wikipede, or Pelthus.
In nature they are extremly territorial, and the males will use their large pincers to hold fights, in a bloody death match, over land, mates, or food. Before going nearly extinct, fossils were found in forest areas just south of Mt. Jetstream. Part of the reason for their low population is that trainers would make them have endless, inhumane, and gruesome fights in small arenas, for the purpose of entertainment.