Lanterns had a special guest appearance during its panel with actor Nathan Fillion bolting onstage and showcasing his cameo. He wore a shirt that stated Best Gardener Ever, a reference to his character Guy Gardener.

“Stop the panel.” Fillion shouts as he walks onto stage breathless and receives praise from the audience. He explains how he has been in different shows such as The Rookie and Firefly.

“There’s a building with my face on it,” Fillion jokes, “I’m legally required to be here.”

A short teaser was shown with Guy in his blonde bowl cut with John Stewart as he relaxes on a bed, although no other context was provided. His character is still being woven into the story.

When asked how he worked with the cast in the middle of filming he said, “when you’re working on a moving train, you’re just hoping everyone is gonna be cool and relaxed and nice and spend your day with people. Everybody is very sweet, very kind to me. And just before they say action, a cloud rolls over and everything gets dower and sinks down and is brutal a bit and then cut and they’re back.”

The panel also included Laura Linney’s role as one of the guardians. The initial news of her casting was in May but know fans officially know who she’s playing!

Fillion has been in roles such as John Nolan in The Rookie, Richard Castle in Castle, Captain Malcom Reynolds in Firefly, a monstrous inmate in The Guardians of the Galaxy, T. D. K in Suicide Squad, Johny Worthington in Monsters University and more!

Stream Lanterns on HBO Max on August 16 2026.