The season two finale of Invincible was packed with plenty of cameos for fans to take in ranging from a not so-subtle Batman reference to Mark Grayson crossing paths with The Walking Dead's zombies. One cameo in particular, though, ended up being watched very closely by Amazon Prime's legal team to make sure it did not run afoul of Marvel, according to Invincible's creator Robert Kirkman.

Kirkman said that the inclusion of Agent Spider during Mark's universe-hoping escapades during the finale was the point of focus for Amazon's lawyers in order to keep the character “legally distinct” from Spider-Man. This included making sure as much detail in his design as possible, down to his color scheme, shared no similarities to Marvel's wall-crawler to avoid potential legal troubles with Marvel and Disney, according to Variety.

Robert Kirkman with scene from Invincible behind him.

The cameo, itself, is a loose-reference to Spider-Man's own cameo in the original Invincible comics, which Kirkman had previously said would not be possible on the Amazon Prime series.

“It was just trying to figure out a way to keep that moment somewhat intact from the comics,” Kirkman told Variety. “It seemed like something that would be a fun and surprising way to do it. Amazon legal, painstakingly, was like, ‘No, the costume can’t be that color. We gotta get away from this and that.' There were a lot of eyes on that scene.”

Friendly, but not from the neighborhood

The scene in question sees Mark come out of a portal into a city alley where Agent Spider is fighting a villain who's appearance bears a striking resemblance to Doctor Octopus. It leads to a humorous back-and-forth between Invincible and Agent Spider as the former tries to regain his bearings before he is attacked by Agent Spider's foe while his back is turned.

Kirkman then explained that the team wanted to cast an actor who had portrayed Spider-Man previously as a “fun thing” for fans to notice, leading to Spectacular Spider-Man veteran Josh Keaton voicing Agent Spider.

“That said, he’s not playing Spider-Man. That’s Agent Spider,” Kirkman said. “There might be some similarities, but I think Josh’s nuanced performance as Agent Spider is completely different than the way he played Spider-Man in Spectacular Spider-Man. But who knows? My opinion may be somewhat biased.”

Invincible's creative team didn't just stop there, though, as the entire finale was littered with cameos and random easter eggs for viewers to catch.

While viewers only see a portion of his cape, it becomes very clear Invincible is speaking with Batman when he begins to break down the DC hero's inspiration and on-the-nose name. Mark then finds himself in another universe surrounded by zombies in a reference to Kirkman's other hit series The Walking Dead, which also starred Steven Yeun in AMC's live action series for seven seasons.

Invincible also managed to slip in a subtle reference to Fortnite when Invincible attacks Angstrom Levy with a Dragon's Breath sniper rifle from the game.

Invincible is available to stream on Amazon Prime Video.