As far as Teen Titans Go!, Green Lantern makes a guest debut in "Real Boy Adventures" during the concert.
While Batman is performing a guitar solo to the crowd (assembled for a concert about Fleshy Guy being a real boy), Green Lantern can be seen pumping his fist to the music, along with other iconic DC Comics characters, such as Nite Owl, The Joker, The Riddler, and others.
Wearing a dark black jumpsuit, Green Lantern has a lot of upper-body strength. The color and wrists of his suit are colored a vibrant green, and on his hand is the infamous lantern ring. He is bald, and looks very serious/intense with his black moustache and beard.
Real Boy Adventures (debut)
Two Parter (costume worn by Cyborg, seen in tank)
Prank'd! (heard, but not seen)
- Green Lantern also appeared in Young Justice, and was voiced by Kevin Michael Richardson and Phil LaMarr in Justice League/Justice League Unlimited.