Aquarus didn't get much face time in Invincible before he was killed by Omni-Man. He was a bipedal fish and the Guardians of the Globe's Aquaman-type character. He got more story after his death than while he was alive. After his murder, Invincible almost had to marry his wife. Atlantean custom demanded that they be wed since Invincible's father had killed Aquarus. The marriage never took place and Aquarus and his kingdom are rarely (if at all) mentioned.