He acted in some movies, especially TV movies, until he began working as voice actor for LucasArts video games, beginning with secondary roles on Indiana Jones and the Fate of Atlantis (1992) and Sam and Max Hit the Road (1993). In this same year, he got some recognition with Day of the Tentacle, where he voiced one of the playing characters (Hoagie), plus all the main tentacles (Evil Purple Tentacle, good Green Tentacle and futuristic Doctor Tentacle).
Delk played a police sergeant in the George Lucas films More American Graffiti and Howard the Duck. While acting in different movie productions during 1994, Delk still had time to do different voice roles in the seventh installment of King's Quest. He also returned to Star Wars with Star Wars: Dark Forces, though not in the main roles: He voiced nameless characters (a stormtrooper, a dying Rebel later identified as Admiral Toka) and the narrator.
Delk worked in four video games in 1995, including two Star Wars games and one other LucasArts game. The fourth was Space Quest VI: The Spinal Frontier. Delk voiced secondary characters in both LucasArts' Full Throttle (Cavefish Maximum Fish and Blotch of the Rottwheelers) and Intercom, and a Red Shirt in Star Wars: Rebel Assault II: The Hidden Empire. However, Star Wars: TIE Fighter allowed Delk to become the villain: Grand Admiral Zaarin, as well as a major supporting character, the Priest.
During 1997, Delk voiced cult-favorite talking skull Murray for The Curse of Monkey Island, and another cult-favorite character for Star Wars fans: Mutant Kowakian monkey-lizard Pic, 8t88 in Star Wars: Jedi Knight: Dark Forces II, as well as other video games plus one movie.
Delk would not return to Star Wars until 1999, where he would reprise Zaarin in Star Wars: X-Wing Alliance. He showed his versatility by playing different Rebel characters, including a pilot, an officer and a Bothan.
Delk also reprised Murray for Escape from Monkey Island, and he worked as the narrator for the Rogue Squadron series (as well as a commander and a wingman in its final installment). He also narrated Star Wars: Empire at War and Star Wars: Empire at War: Forces of Corruption (2006) and voiced the training officer in Battlefront II (2005).
He returned to the role of Murray in 2009 in the episodic adventure game Tales of Monkey Island in the episode Lair of the Leviathan.