The British comedian, 53, was cast as the beloved Hogwarts groundskeeper in the new HBO Harry Potter TV series in April 2025, but his work to get the role started way before that. "So last Christmas, I watched all the films back to back on the Sky Harry Potter channel, while writing out the word 'Hagrid' 7,000 times," Frost revealed. Nick Frost as Rubeus Hagrid on the set of HBO's 'Harry Potter' series. Frost also wants his portrayal of the character to reflect how "funny" Hagrid is. HBO's Harry Potter series is slated to premiere in 2027.