Albedo is a Galvan from the planet Galvan Prime. When he did not look like the clone of Ben Tennyson, he was the assistant of Azmuth. When Azmuth finished the Omnitrix, Albedo wanted him to create one for himself, saying that Ben 10 could not be trusted with the Omnitrix. However, Azmuth refused and told him that there can only be one Omnitrix. Albedo did not listen to Azmuth, instead he created his own Omnitrix. When he activated his fake Omnitrix, Albedo instantly turned into a clone of Ben 10, because the original Ominitrix had merged with Ben's DNA. Due to this uncomfortable situation, Albedo traveled to Earth so that he could kill Ben, and take his Omnitrix so that he can revert back to his Galvan form. When they confronted, Albedo's Omnitrix connected to Ben's causing Albedo to turn into a silver haired Ben Tennyson, but with a red jacket. After Ben defeated Albedo, Azmuth sent him into a prison cell and destroyed the fake Omnitrix. The last thing we see from Albedo, is him in his cell, yelling out, "BRING ME CHILI FRIES!", something Albedo picked up from being a "clone" of Ben Tennyson's, as Ben enjoys Chili Fries a lot.
Albedo was also the one to first use the Ultimatrix.
Albedo debuted in Alien Force where he, as Humongosaur, attacked Forever Knights asking for Ben Tennyson's whereabouts. Later in the episode he engaged with Ben in a battle, where he won because Ben's omnitrix timed out. Azmuth arrived and deactivated Albedo's omnitrix trapping him in human form.
Albedo once again appeared in The Final Battle, where he teamed up with Vilgax. Albedo now had a different version of Omnitrix, which he called "Ultimatrix." He used it to evolve Humongosaur and defeated dozens of Humngosaurs easily. However he was overpowered by them in end because of their sheer number. Later after Ben threatened to blow up Ultimatrix using voice command, Albedo gave him the ultimatrix.
Albedo was posing as Ben on a TV show with a Vaxasaurian (Humongosaur's species). Ben found out and confronted him about it, to which Albedo said, he was trying to live. Albedo somehow ended up transforming into Rath without any ultimatrix and fled.
Albedo made his omniverse debut in episode The Ultimate Heist where he had managed to switch place with Ben. He was after a device which was being transported by Ex-Weapon Master Inspector 13. He managed to get them in the end allowing him to transform into Ultimate forms. He was however defeated by Argit who attacked from behind. He was rescued by Khyber, who made his first appearance after his defeat. In the end Albedo managed to evolve himself into Ultimate Albedo. Ultimate Albedo was able to fly and had three eyes. Albedo claimed even Azmuth won't be as intelligent as a hyper evolved galvan.