What is "aballin"

In the Dungeons & Dragons fantasy role-playing game, most commonly the Forgotten Realms campaign setting, the Aballin is an ooze. They resemble large puddles of stagnant, jelly-like water. (They are actually oozes though, not elemental creatures of water, because their substance, though it resembles water, is actually an acid.) They were supposedly created in ancient times when a druid fell victim to an archwizard's curse and turned into the first aballin. All other aballins are thought to be descended from her.