Mytherian is a spiritual, enchanting, and supernatural Psymonster who considers himself to be a professional wish consultant of the Psymonster World. He will grant the conceivable spoken wishes of any Psymonster who rubs his magic red bottle, but he likes to make sure that any Psymonster is wishing really knows what they are getting themselves into. He doesn't want there to be any ridiculous wish mistakes on his watch. The official rules say that Mytherian isn't allowed to tell any Psymonster what to ask for, but he can still nudge wishes in the right direction by pointing out their possible accidental downsides, and any Psymonsters wouldn't want to ask for superpowers and get a corresponding acceleration, or wish for a giant castle, and end up with something that is underwater. Once some Psymonsters pick the right wish, all he has to do is wink, and it is granted.
He is a blue magic genie with teal eyes, a dark purple ponytail, eyebrows, a mustache, and a beard, an indigo mouth with a violet tongue, a magenta vest with gold buttons, a gold belt with a yellow star, a red bottle held by his belt, and a turquoise bead on his ponytail.
- The name "Mytherian" is probably derived from the word "myth", meaning a traditional story, especially one concerning the early history of a people or explaining some natural or social phenomenon, and typically involving supernatural beings or events.
- He is very similar to Genie from Disney's animated series, Aladdin.
- Both have blue skin and ponytails.
- Mytherian is one of the 44 Psymonsters who have no legs (the other 43 are Planto, Zoidburger, Gingersnap, Sundrift, Catfish, Colossus, Putty, Snakegrowth, Mystical, Waxcandle, Angler, Robotical, Sheloden, Kennywheel, Sprout, Scary, Thunderquake, Cobracious, Creaturous, Greedy, Queasy, Transparent, Watermelody, Aquamarvelous, Trampedo, Waxcleaner, Oceanquake, Lunar, Snowmelter, Drivacuum, Slash, Stumpback, Elasmountain, Concordian, Conqueror, Puffy, Schizophobia, Tester, Booter, Telephone, Extraordinarium, Bargeria, and Coolberry).