"I'm working on four characters right now. I’m working with Josh Brolin and three other actors," he told The Hollywood Reporter, "and I’m playing Josh Brolin’s right-hand bad guy in the film. I can’t say the name of the character or I think Marvel will sever my head, but I apply those same principles of what it means to drop bullshit and just play a character truly evil. And it’s working. It’s truly working."
While Notary declined to list his specific role, IMDb.com lists him as "Cul Obsidian/Groot." While that should be taken with a grain of salt, given Notary's reference to "Brolin and three other actors," it's possible he's playing a member of a reduced version of the Cull Obsidian, or Black Order. In Marvel Comics lore, the Cull Obsidian is a team of five generals sent by Thanos to subjugate Earth during 2013's "Infinity" event.
In a 2013 interview with CBR, Marvel Executive Editor Tom Brevoort described the members of the Black Order as "existin[ing] on a galactic scale." "They’re not necessarily Titans like Thanos, but they are beings of the cosmos who walk in the same circles as Thanos," he said. "They’re unto like demigods. They’re just as sturdy and undamageable and knowledgable as guardians. These aren’t normal aliens, these aren’t basic Skrulls or Kree or average Shi’ar. These guys are levels that are one-up from that."
Given Notary's past motion-capture work, which includes his "Kong: Skull Island" role, a goblin in "The Hobbit" films, and Rocket in "Rise of the Planet of the Apes," it's likely his Marvel Studios role will also be motion-capture.
Directed by Anthony Russo and Joe Russo, "Avengers: Infinity War" arrives in theaters on May 4, 2018. It stars an ensemble cast that includes Robert Downey Jr., Mark Ruffalo, Chris Pratt, Jeremy Renner, Benedict Cumberbatch, Brie Larson, Josh Brolin, Karen Gillan, Zoe Saldana, Tom Holland and Pom Klementieff.