Samus Aran

Samus Aran is an intergalactic bounty hunter who occasionally visits the Mushroom World.

In Super Mario RPG, Samus traveled to the Mushroom Kingdom to stay at the guest room of the royal castle. Apparently, Samus needed a place to rest before battling the evil Mother Brain.

Interestingly enough, the maniacal Booster owns a Samus Aran doll.

Samus also appears in Super Smash Bros. and Super Smash Bros. Melee, as a playable character. It is unknown if she will appear in Super Smash Bros. Brawl.