Perspective

An attempt at humour

Saw the vampire bat

While killing bats as a rat.

I returned fully armored with 3 mercenaries.

While the bat spawns inside the cave, it can wander between zones, which is pretty cool. It can also drop a fang which crafts a "potion of recovery", which apparently heals a player's health to full. That would be very powerful in the hands of a top-ten player, and could be a good income source for mid-levels.

Aberoth adverts

(Using stuff from Nintendo Power, and Saywhoo)

Batman

He was able to achieve this by inviting a lot of players and having them summon bats. It lagged the other vaults, but it was gone when I logged on the next day, so they must get removed somehow.