Ralph Domzalski is an unseen character in Trollhunters.
He was the son of Nancy Domzalski, the husband of Mrs. Domzalski, and the father of Toby Domzalski who (along with his wife) became lost a sea when their cruise ship got caught in the middle of a storm.
When Toby was about two years old, Ralph and his wife won the state lottery. To celebrate, they both then went on a cruise together around world, but there was a storm, which they unfortunately got caught in. And were presumably killed as Toby mentions that his parents never made it back.