In an interview with Michael Madsen, the voice actor for William Carver, he revealed that he is friends with actors Michael Rooker and Scott Wilson from The Walking Dead TV series. He stated that he wanted to get a part in the TV series, but didn't get the role.
The corpse that Nick inspects in Spoiler:"All That Remains" is a reused model of Spoiler:the dead husband in Season 1, Episode 5 "No Time Left."
In Episode 6, "All That Remains", Clementine will say one of two different lines when dropping the bottle of water in the restroom. These are "Oh, shoot!" or "Oh, shit!", depending on whether the player mentioned the term "shit" to Clementine on Hershel's farm in Season 1, Episode 1, "A New Day".
In episode 3, "In Harm's Way", the comic book store beside Howe's Hardware has a large number of comics, including "Invincible", "Ghosted", "Super Dinosaur" and "Manifest Destiny". There are all real-life comics published by Image Comics and Skybound, the same imprints of The Walking Dead comics.
During the scene where Nick, Pete, and Clementine Spoiler:discover the corpses at the lake, Roman's corpse from "400 Days" can be found.
Spoiler:When hacking off Sarita's Arm at the end of "In Harm's Way", her screams are actually reused from Beatrice's screams from The Walking Dead: Season One episode, "Long Road Ahead".