Hypno-Puffle was made into a Battler by Ernie, even before he joined the EFP. He wanted to know how to control people with simple flashes, and invented goggles that would allow him to do so. However, the glasses wouldn't work, and he gave them to his pet puffle. The puffle found out how to use them, and Ernie took advantage of this and made it a battle-puffle. For the first few rounds, he did splendid, but one of the battle-puffles it fought later was a blind Kung-Fu master and was immune to the glasses. The blind puffle horribly injured Hypno-Puffle, and Ernie felt bad and stopped him from being in battles.
Later when Ernie joined the EFP, he became very busy and could not take care of Hypno-Puffle as much as he did before. HP waited for a while, but then gave up hope of Ernie being able to treat him normally, so it ran off. It took advantage of its glasses and hypnotised many penguins and puffles to do its bidding. Hypno-Puffle then realized how much joy it had being a battle-puffle, and rejoined.
Hypno-Puffle kept doing its crimes of hypnotizing penguins and puffles to be its servant. However, it later met Ernie (who now has a cactus for a head). Hypno-Puffle stared at the grotesque creature, and then decided to hypnotize it. However, Ernie, being immune to his own inventions, felt nothing, and Hypno-Puffle realized its old master. Ernie apologized for not being there for it, but now that he "quit" the EFP, they can spend more time together. Hypno-Puffle forgave him and never used its powers outside the Battlerina again.