Albert

Pop-Pop is the grandfather of the Loud kids.

Biography
Pop-Pop is first mentioned in "Chore and Peace" by Leni, when she mentions Lincoln's white hair.

In "Cover Girls" he makes his first on-screen appearance. He makes a video call through the computer to talk with his grandchildren. Because he wasn't using his glasses, he couldn't recognize better the Loud children, who were dressed up like the other sibling.

Appearance
Pop-Pop is a burly man with white hair and a large tuft of his hair that sticks up much like Lincoln's hair. He also has gray mustache and gray eyebrows as well. On his right forearm he has a tattoo of an anchor.

He wears a white button-up shirt, blue jeans with a black belt and orange suspenders. He also has glasses hanging on his neck when he's not using them.

Trivia

 * The color and style of his hair is exactly like Lincoln's.
 * Pop-Pop seems to be unaware that his glasses are hanging from his neck, which evident when he says when he needs to find his glasses the next time he contacts the children.
 * He calls Lincoln his look alike.