There are over 600 of these braindead suckers, so when I say best zombies Im narrowing it down to the absolute best
Once you have a Gyarados ready to go, it's almost impossible for the opponent to recover: Gyarados' energy discarding effect sometimes stops them being able to attack at all once their first Pokmon goes down
Spore Swarm 3.5 Not great, the instant is cute but not often that relevant
Japanese cards are sometimes cheaper due to smaller local demand, bulk print editions, and direct availability in Japan
Brionac, Dragon of the Ice Barrier allows players to discard any number of cards to the GY, then target a number of cards up to the cards discarded and return them to the hand
The only caveat is that it takes a lot of skill on the part of the player to understand its true potential as a game-changing card