There are a LOT of Missingno in Generation I. 255 Pokemon slots, but 151 Pokemon. 104 Missingno. The Special stat of 182 gets the Kabutops fossil Missingno. 183 gets Aerodactyl. I think 184 gets the ghost. As in, the "ghost" you run into in the Pokemon Tower if you don't have Silph Scope. But it's named Missingno.