Albedo/Earth-69

Albedo is a Galvan from Galvan Prime (now Galvan Mark II) who, after a failed attempt to recreate the Omnitrix, was trapped in Ben Tennyson's human form.

He first appeared in Albedo Returns.

Ben 10: Alien Universe

 * Albedo Returns (first re-appearance)
 * Homesick Trilogy: The Final Part

Back in Action: Alien Universe

 * No Strings Attached (first re-appearance)
 * The Sea's the Limit (Endgame only)
 * Hit and Miss (Endgame only)
 * Operation Pyros (main character)
 * Dial Z for Zombified (Endgame only)
 * Missing Link
 * New Girl