The best Evo Bats deck right now runs them with Minion Giant, Poison and Rune Giant. It's also the most played Evo Bats deck.
Evo Bats
Overview
“Spawns a handful of tiny flying creatures. Think of them as sweet, purple... balls of DESTRUCTION!”
Ability
Evolved Bats gain +50% Hitpoints and start healing themselves twice a second after attacking, an overheal effect that can push them past their normal max health.