Maze of Muertos

FLIP: Inflict 400 damage to your opponent for each card in their hand.

Des Koala

Speed Duel GX: Duelists of Shadows

If this card inflicts battle damage to your opponent by battle with a monster: Gain LP equal to the battle damage inflicted.

Vampiric Koala

Speed Duel GX: Midterm Paradox

Once per turn: You can target 1 monster your opponent controls; change its ATK to 0 until the end of this turn. You must control a Beast-Type monster (other than this card) to activate and to resolve this effect.

Sea Koala

Speed Duel GX: Duel Academy Box

A species of huge Des Koala. He's meek, but people are afraid of him because he's very powerful.

Big Koala

Master of Oz

Order of Chaos: Special Edition

"Sea Koala" + "Tree Otter"
You can send 1 Beast-Type monster from your hand to the Graveyard to target 1 monster your opponent controls; destroy it.