Little Mac

Little Mac is a human boxer from the Punch-Out!! series, he has had several encounters with Mario and other characters from the Mario series. He first appeared in the NES title in the Punch-Out!! series, which was originally titled Mike Tyson's Punch-Out!!.

Mike Tyson's Punch-Out!!
Little Mac made his debut in Mike Tyson's Punch-Out!! and fought through many tough foes, while Mario served as a referee.

Punch-Out!! (Wii)
In Punch-Out!! for the Wii, like the original version, Mac once again fought many tough foes to become the world champion. His final match was, surprisingly, against Donkey Kong, who'd somehow managed to take him to the top.

WarioWare: Smooth Moves
WarioWare: Smooth Moves features a microgame named "Punch-Out!!" based on the game of the same name. In it, the player, as Mario the referee, has to count out the boxers knocked down by Little Mac. When successful, Mac cheers his victory.

WarioWare: D.I.Y. Showcase
He appears in the microgame Punch-Out!! in WarioWare: D.I.Y. Showcase.

Super Smash Bros. Brawl
Along with many other Nintendo characters who didn't have many appearances, Little Mac returned in Super Smash Bros. Brawl. Here he was an Assist Trophy who would emerge and punch many times at the enemies of whoever released him, until he delivered one final blow that would nearly always KO them.

Super Smash Bros. for Nintendo 3DS / Wii U
After having only appeared in the previous game as an Assist Trophy, Little Mac was confirmed as a new playable character in Super Smash Bros. for Nintendo 3DS / Wii U on February 13, 2014, the day of the Japanese release of Donkey Kong Country: Tropical Freeze (to reference his relationship with Donkey Kong). Little Mac features a Power Meter that, when charged up, changes his neutral special attack to a one-hit KO uppercut. His Final Smash is Giga Mac, a form that first appeared in Punch-Out!! on the Wii.

Captain Rainbow
In Captain Rainbow it is revealed that by the events of this game, Little Mac had been out of work for some time and had become largely obese. It was up to the game's protagonist Nick to help him get back into shape.

NES Remix 2
In the Wii U downloadable game NES Remix 2, Little Mac will make an appearance in the mini-games based on the original Punch-Out!! game, one of which requires the player to knock out Glass Joe.