Samus Aran

Samus Aran is the main character from the Metroid series. She was raised by the Chozo, an ancient race of bird-like people, and goes through dangerous missions throughout the galaxies, such as saving planets and bounty-hunting. She appears in Kirby's Dream Land 3 as a cameo, and is a playable character in the Super Smash Bros. series alongside Kirby.

Kirby's Dream Land 3
In Kirby's Dream Land 3, Samus Aran wants Kirby to exterminate a horde of Metroids in exchange for a Heart Star. The Metroids can only be defeated using the Ice ability, a reference to how they are destroyed in the Metroid games.

In the Super Smash Bros. series
In the Super Smash Bros. series, Samus is a starting playable character in all five games. She hails from the Metroid series as the first and only playable character of it (not counting Zero Suit Samus, as she is just Samus without her powersuit and its moveset). She has projectile attacks such as her Charge Shot and Missiles that cover a wide range of space.

Her design in the first two Super Smash Bros. games was based on her look in Super Metroid, Brawl used a blend of Metroid Prime and Metroid: Zero Mission's suits, and her design in Super Smash Bros. for Nintendo 3DS and Wii U reflects her design from Metroid: Other M.

Trivia

 * One entire stage in Iceberg that revolves around having to defeat all the Metroids in Kirby's Dream Land 3 is a reference to Metroid II: Return of Samus, where Samus' mission is to destroy all the last Metroids on SR388. She rewards the player with a glimpse of her helmet off, and because all the Metroids in the area have been exterminated, her mission is complete. In the Metroid games, when all of the items are obtained fast enough, the reward at the end is seeing Samus without her helmet or even her whole suit. This is basically the same concept.
 * In Kirby Super Star and Kirby Super Star Ultra, a rare, golden statue of Samus can appear while using the Stone ability.
 * A treasure in The Great Cave Offensive, the Screw Attack (misnamed "Screw Ball" in the English version of Kirby Super Star), is an item Samus equips in the Metroid games to be able to spin rapidly in the air, reaching many places and destroying enemies upon contact.