Poo is a playable character in the 1994 role-playing game EarthBound for the Super Nintendo Entertainment System. He is the fourth of the "chosen four" children that were prophesied by the Apple of Enlightenment to defeat Giygas and save Earth, and the last playable character to join Ness' party. Poo is the crown prince of Dalaam, a rural country in the Far East. Under the tutelage of his master, Poo has spent much time training in the martial arts as well as developing his psychic abilities.
During the course of the story, Poo is introduced just before undertaking the final trial as part of his training regimen: an frighteningly-intense meditation session where he must ignore all distractions and submit to the will of his ancestor spirits. Once his training is complete, Poo is instructed by his master to teleport to the party's location in Summers, where he swears his allegiance to Ness. After completing Scaraba's Pyramid later in the game, Poo leaves the party temporarily for special training with the Star Master, who teaches Poo the powerful PSI Starstorm technique.
Poo is a capable physical fighter and can also use a wide variety of offensive and defensive PSI powers. His special command is to "Mirror" certain enemies, turning himself into a clone of the enemy that acts independently and can use that enemy's special abilities. Poo also has a high resistance to Fire and Freeze-based PSI attacks. Because of Poo's exotic origins, he is unaccustomed to western-style food; as a result, Poo recovers substantially fewer hit points when consuming food items with the notable exception of the Brain Food Lunch. However, unlike the other party members, Poo can recover his PP (Psychic Points) significantly by drinking Bottles of Water.
Poo cannot equip standard weapons or armor such as yo-yos, charms or bracelets. Instead, Poo must locate the individual pieces of a special "Kings" set of gear found in various locations throughout the game. Poo's weapon, the Sword of Kings, can only be obtained as a random item drop; this infamously-rare weapon only has a 1-in-128 chance to drop from defeated Starman Supers inside Stonehenge Base. Poo also joins the party while carrying the "Brain Stone", a unique passive item that prevents enemies from disrupting one's concentration while using PSI.
Poo makes an appearance in Super Smash Bros. Melee as a trophy; he also appears in Super Smash Bros. Brawl as a sticker.