Alph (アルフ, Alph) is the first of the three protagonists of Pikmin 3. He was the engineer on the S.S. Drake as well as the youngest crew member. After getting stranded on PNF-404, the world of Pikmin, it fell to him to reunite the crew, get the fruit they were sent to obtain and repair the ship's warp drive. The crew end up running into and saving Olimar in the end.
In Pikmin 3, a group of three, consisting of Alph, Brittany and Charlie, are tasked with saving their home planet of Koppai as their food supplies become near depleted. When data collected reveals that a distant planet, given the name PNF-404 (which also happens to be the home planet of the Pikmin), is rich with a variety of fruits whose seeds can be cultivated on Koppai to end the food shortage, the crew of three travel to the alien planet in the S.S. Drake. However, their ship malfunctions and they become separated just before landing, with the cosmic-drive key also being lost, which is mandatory for leaving the planet. Over the course of the game, Alph reunites with Brittany and Charlie, collects fruit, harvesting their seeds and using their juice for sustenance while on the planet, and eventually meet up with Louie, and later on Olimar, who they rescue from the Plasm Wraith. As thanks, Olimar gives them their lost cosmic-drive key, allowing them to return to Koppai safely with their findings.
In Super Smash Bros. 4
Four of Olimar's alternate costumes replace his model with Alph, making him an alternate form of a playable character. He has his own alternate palettes as well, having ones resembling his crew-mates Brittany and Captain Charlie, and his third alternate palette resembling Olimar. Despite using a different ship, the S.S. Drake, in Pikmin 3, Alph still uses Olimar's Hocotate Ship for his on-screen appearance and Final Smash. He has a trophy using his playable model, classified under the fighters category, but it is obtained in the Trophy Shop rather than as a reward for clearing classic mode, similar to the Koopalings.
According to translated design documents, Alph was planned to be included as a clone character like Lucina and Dark Pit, instead of just being an alternate costume for Olimar. Rock Pikmin were additionally planned to be included, where they would be heavy and short-ranged, but very powerful. Neither idea ended up implemented in the final game, presumably due to time constraints.