Raw Adamantine trees?

On a serious note, you could try Knockout breath attacks. Made of magma. well who doesnt like magma anyway?
Also> my brain has thought of an amazing idea. a MAGMA FOUNTAIN!? lmfao a creature that squirts magma.. no idea if it's possible but would be totally funny to see in the arena. Oh and Bronze Collosi + Magma = Bronze puddle

now pitting a dragon vs Magma creature of doom. that would be hilarity insured not to mention 50 elves in the middle going: "

WHO TO KILL. oh i'll kill my
meatshields friends.."
Also why not creature the Mystical beast? 600 arms? maybe? can fly? Dragon breath? Made of adamantine? would be funny to watch it tearing things to pieces.