Guy's lover is played by Michael Dorn, best known for his role as Worf on Star Trek: the Next Generation (1987) and Star Trek: Deep Space Nine (1993). During the Comic-Con scene, he cosplays as this character.
For the scene where Ted hides from Donny among other Ted plushes, the production purchased commercially available Ted plushes and then added a new mouth for each one with CGI to match the movie Ted's appearance. This saved money as opposed to creating more original ones for filming. This is mentioned in the commentary.
When Ted steals a cellphone to call Johnny for help, the ringtone on Johnny's phone is the Knight Rider (1982) theme, which is the actual ringtone Seth MacFarlane uses on his own cellphone in real life. In the blooper reel of A Million Ways to Die In the West (2014), during the climactic showdown scene, MacFarlane's cellphone, which he had in the back pocket of his costume, went off twice and the audience can hear the theme playing clearly. Four actors and actresses from this movie also starred in A Million Ways to Die In the West (2014).
John spills vials of sperm on himself as the shelf collapses. This scene is similar to Family Guy: Sibling Rivalry (2006), in which the exact same thing happens to Peter Griffin, who is also voiced by Seth MacFarlane.
The scene where Sam plays the guitar while singing in the countryside, is similar to the film The Sound of Music (1965), where Maria does the same thing to the van Trapp children. The Sound of Music (1965) is Seth MacFarlane's all time favorite movie. In fact, Seth loved the film so much, Family Guy (1999) played cutaway gags based on the film.
In the court scene, where Ted looks to use "Beetlejuice" to get out of trouble, he actually says Beetlejuice six times, which is the same as in the movie, where Geena Davis says Beetlejuice three times to make him appear, and three times again to make him disappear. This would explain why it didn't work.
The movie is a mini tribute and reunion of Star Trek. Sir Patrick Stewart, who played Captain Jean-Luc Picard on The Next Generation, is the narrator, Michael Dorn, who played Worf in Star Trek: The Next Generation, and Deep Space Nine, is Rick. He also dresses as his old character in the Comic Con scenes. Nana Visitor, who played Major Kira in Deep Space Nine, is the adoption social worker, Ron Canada the judge, appeared in Star Trek: Voyager and Deep Space Nine as an episode alien, Bill Smitrovich, who played Frank, appeared in Deep Space Nine (S3,E11, E12). During a New York City street scene, Ted's attorney erroneously refers to dressed up Star Wars zealots as Star Trek fans. The tribute comes to a crescendo in the final Comic Con scenes, when various Star Trek characters, separated by series and centuries, are fighting each other. This culminates with a mock up of the Enterprise-D falling and threatening to hit Ted.
In both "Ted" movies, you hear a main theme song from two very popular movie franchises. In Ted (2012), you hear "The Imperial March" from Star Wars: Episode V - The Empire Strikes Back (1980) when Johnny's cell phone goes off. Here, the main Jurassic Park (1993) theme can be heard when the main characters stumble across a large field of marijuana.
When Sam is playing the guitar, and singing in the countryside, all the little animals gather round to listen. The song and chord structure is very similar to the scene from ¡Three Amigos! (1986), when, Chevy, Steve, and Martin sing the cowboy lullaby "Blue Shadows on the Trail".
When the police are called by dispatch, they are called on a "317." The police say that a "317" is when someone is trying to steal Tom Brady's sperm. 317 is the area code for Indianapolis where the Indianapolis Colts play. The team and ex-Colts quarterback Peyton Manning are big rivals of Tom Brady and the New England Patriots.
While Sam sings in the country side this attracts several animals. This also happened in Disney's Snow White and the Seven Dwarfs where Snow White is greeted by the forest animals while she sings 'With a smile and a song'.
Ted being carried into the air by a goose is similar to the scene of the Wizard of Oz where Dorothy gets lifted by the flying monkeys. Plus Ted going to New York to see Partick Meighan to win his case only to be originally turned away similarly happens in the Wizard of Oz where Dorothy and her friends go to the Emerald City to get Oz to grant their wishes only to be originally rejected.
When Ted, John and Sam arrive in New York City they meet three men dressed up as Star Wars characters Obi-Wan Kenobi, Darth Vader and a Storm Trooper. In the previous film during the opening credits Ted and John were seen dressed up as Yoda and Darth Maul also of Star Wars respectively. Liam Neeson who played the customer buying Trix and Samuel L. Jackson who is mentioned starred in Star Wars as Quin-Gonn Jinn and Mace Widu respectively.
Amanda Seyfried's character mentions that she graduated from Arizona State University. The ASU Sun Devils marching band performed during halftime at Super Bowl XLIX (2015), a game the Patriots would go on to win.
In the beginning of the movie, we see Ted (voice of Seth MacFarlane) and Johnny (Mark Wahlberg) making up words to the original Law and Order show on TV. In Season 6, Episode 5 of Law and Order SVU, "Outcry", Amanda Seyfried (Samantha) played teenager "Tandi McClain."
The person that is used as a battering ram to knock Patrick Warburton and Michael Dorn into the glass case in the Comic Con fight scene is wearing an over-sized mask of the Toxic Avenger, as featured during the end credits of the movie Return To Nuke 'Em High A.K.A. Part 2, and was supplied by the creator of the Toxic Avenger, Troma Entertainment, INC.
When in a diner Sam for a prank tossed a cookie crisp into a blind customer's bottom only for him to feel it and demands to know who was responsible. A similar incident happened in Dumb and Dumber when Harry accidentally hits Sea Bass with a salt shaker and gets confronted by Sea Bass.
Ted going to court to appeal being 'human' could be a parody to Kramer v Kramer as both films have a protagonist named Ted who go to court to earn the right being 'human' and winning a custody battle respectively. In both films the characters originally lose their cases but each get a happy ending as Ted in this film earns his rights on being 'human' while Ted Kramer in the latter film is given custody of his son by his ex wife. Plus both characters have their marriages ended although it is implied Ted in this film remarried Tami Lynn.
The trivia items below may give away important plot points.
Mila Kunis did not come back to play Lori because she was pregnant. In an early draft of the script, someone mentions that Lori died between the two films. That idea was considered too depressing, so it was changed to John and Lori getting divorced.
When the trio are stranded at the pot farm, Amanda Seyfried really sings her character's song. "Mean Ol' Moon" was written especially for the film, and the lyrics were penned by Seth MacFarlane. In an interview with USA Today, Seyfried said "It took like a week, but we did it, and it actually works."
One of the depressing suggestions at the improv show is "9/11". Mark Wahlberg and Seth McFarlane were scheduled to fly on American Airlines Flight 11 that morning, but both didn't make the flight through change of plans and missing the gate time respectively.
When John, Ted and Samantha find the marijuana field. The movie recreates a scene from Jurassic Park (1993) where Alan and Ellie first see a dinosaur shot for shot. John discussing the weed shouldn't be there references Ellie discussing how a plant she found has been extinct, Ted moving John's head recreates Alan turning Ellie's head, then then theme from the scene is playing and like in JP Ted is amazed to see "They do move in herds" which was a line Alan said.
During the Comic-Con fight sequence, there is a quick shot of Peter Griffin fighting a giant chicken on the right side of the screen. This is a reference to Family Guy (1999), which Seth MacFarlane created, where Peter and the chicken would randomly get into extended fight sequences.
Tara Strong voices Ted whenever he says "I love you". Strong also voices Twilight Sparkle in My Little Pony: Friendship Is Magic (2010) which was created by Hasbro. My Little Pony references appear throughout the movie at the Hasbro headquarters and New York Comic Con.
The scene at Comic-Con, where a huge flat screen lands on John and nearly kills him, is an homage to the first Ted, where John and Ted are fighting and a television knocks over, and lands right on top of John.
There is a scene in the film, where Tom Brady throws Ted from his balcony. Ted is wearing a yellow raincoat and hat in this scene. However, when the scene was shown in the film's previews, Ted was not wearing anything.