From the introduction:
The story of Heavy Metal is the story of the Lochnar. While it appears as an innocuous, oversized glowing green marble, it is in fact far worse.
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The sentient Lochnar has powers unimaginable. It can melt the flesh off a person almost instantaneously, though it at times chooses not to as well. (When the Professor's daughter showed it to Harry, neither were hurt by it.) It can also transport people to other planets, other dimensions, and completely change bodies' age, sex, size, and color and sometimes personality. It can speak, can restrain movement, can fly of its own volition and is capable of reanimating the dead (creating zombies.) Above all, the Lochnar prefers to corrupt through greed and love of power.
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Like all villains, its overconfidence is its weakness. The Lochnar has a propensity for gloating, especially in the presence of its enemies the Terrakian. Once a thriving race, now there is only ever one Terrakian, and she is always female.