Zombies and Zwambies

Zombies
Zombies have a chance to spawn in caves at any depth other then between 600 and 1000 blocks. Killing them causes them to drop ores, and give you 5000 xp.

Zombie ore drops
They can drop opal, gold, diamond, emerald, and topaz.

Zwambies
Zwambies spawn in caves between 600 and 1000 blocks deep. They are nearly the same to zombies, but they explode. Killing them grants 20000 xp.

Zwambie ore drops
If i, the owner of modded mines (Superguestman124) am correct, they drop the same things, but with boomite added to the mix.