Pokémon Infinite Fusion

Pokémon Infinite Fusion is a Pokémon RPG fangame based on the Pokémon fusion generator trend, featuring sprite art from a large community of artists. In this version of Pokémon, Silph Co. has created a DNA splicer that can work on any Pokemon, allowing their stats, visual appearance, and typing to be combined alongside their available abilities and moves. The game includes both the Kanto and Johto regions, and includes over 570 Pokémon, including the first 386 Pokémon from the first three generations alongside a suite of specifically chosen Pokémon from later generations.

With hundreds of thousands of fusions available, even Professor Oak doesn't expect you to "catch 'em all"!