First up we have Mermaid Man. The old hero in Spongebob Squarepants world is a combo of Batman and Aquaman. He's not Aquaman so he already has a leg up. His powers have decreased with age, but he still manages to get around.
Then we have Aquaman. I think it's safe to say we know what he's about. Butt of many a joke, this "King of the Ocean" has become more prominent with Blackest Night.
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