The title says it all. Pick an animal (real, extinct or mythical), object or what ever and make it a pokemon by giving it a type, ability, stats and even movepool.

I'll start with a Spinosuarus.
>Type: Rock/Fire
>Ability: Solar Power
>Stats
HP: 75
Atk: 100
Def: 85
SAtk: 100
SDef: 60
Spd: 90
BST: 510