Crimson Geode
From Golemagg the Incinerator. Therazane wore these spunky crimson elementals as jewelry before the azure craze swept through Deepholm. Elemental type.
The Crimson Geode is a wild battle pet found in Deepholm that can only be encountered as a direct challenge, never appearing as a secondary pet in another battle.
Guide awaiting review
Travel to Deepholm
Head to Deepholm and look for Crimson Geode spawns in the wild. It does not appear as a secondary pet, so you must find and challenge one directly.
Prepare for self-damage
The Crimson Geode has multiple attacks that damage both your pet and itself, meaning it can kill itself before you capture it. Let it damage itself down into capture range rather than attacking it, which maximizes the number of turns you have to attempt a catch.
Use crowd control early
Abilities like Food Coma that incapacitate the Crimson Geode are especially useful here, since they prevent it from using its self-damaging attacks and dying before you can throw a trap.
Hunt for a rare quality
A rare blue-quality Crimson Geode is extremely difficult to find — out of 338 battles, only 2 rare specimens were encountered, and both killed themselves before being caught. If either a rare kills itself or you accidentally kill it, it cannot be recaptured. An alternative rare-quality option is the Elementium Geode, obtainable through mining, which shares the same attacks.
Tips
The best breed for pet battles is P/P, but the Crimson Geode also comes in H/H, H/P, and H/S breeds.