So I turned my friends name around backwards for fun and we ended up going on a long tangent about this new pokemon.

Nyrat is a horde type pokemon. To evolve it you need a team full of Nyrats, the one leveled would carry its IV and behavior to the next evolution.. which would be a mass of Nyrats a la Dugtrio as one pokemon.

The final evolution would be a three headed Rat cerebrus type pokemon. All of which I haven't drawn but the idea was fun.