Shiigan's name comes from the words sea and Gigan.
Shiigan has a Gigan-like appearance, sporting scythe hands, spikes on their backs, and a similar head.
Shiigan is the result of an alien substance mutating zooplankton.
Shiigan has the abilities to let out a poisonous fluid spray from his mouth and the power to fire energy blasts from his tail.
- Due to the fact that Shiigan has reptilian and insect features and has blades for hands, Shiigan bears some resemblance to the Pokémon Scyther, and also, rather obviously, Gigan.