While “Avengers: Age of Ultron” hid many hints at what is coming for the next phase of the Marvel Cinematic Universe, director Joss Whedon also sneaked in a few references to classic films ranging from “Frankenstein” to “Star Wars: The Empire Strikes Back.” Beyond Thanos and the impressive Hulk-size box office, here are a few of the many movie homages squeezed into “Avengers: Age of Ultron”:

[WARNING: Major Plot Spoilers Ahead!]

1. “No Strings on Me” song from Disney’s “Pinocchio”
When Ultron (James Spader) starts to become sentient, he attacks the Avengers and is able to escape into the ether thanks to the Internet. “No strings” will hold this bad guy down.  

2. “Star Wars: The Empire Strikes Back” hand cut
It's not as revelatory as “Luke, I am your father,” but when Klaue (Andy Serkis) cleanly loses his hand thanks to Ultron in Wakanda, it does look vaguely familiar. In fact, as Cinemablend has compiled, there’s at least one hand lost in every Marvel Phase 2 movie.

3. The doorway from “The Searchers”
In the end of John Ford’s classic 1956 Western, Ethan Edwards (John Wayne) returns his niece (Natalie Wood) to safety, but is unable to go inside the house himself, feeling as though he doesn’t belong in that world. Likewise, when Hawkeye brings the Avengers to safety, Captain America (Chris Evans) is unable to enter the family home, and chooses instead to turn around and stay outside.

4. Vision brought to life, “Frankenstein” style
“It’s alive! It’s alive!” After arguments erupt about whether or not to bring Ultron’s creation to life, Thor (Chris Hemsworth) takes matters into his own hammer. The thunder god summons a bolt of lightning to bring Vision to life reminiscent of the 1931 horror movie classic.

5. Heroic train stop scene from “Spider-Man 2”
During the frantic scene in Seoul to stop Ultron from unleashing his new evil prototype, Scarlet Witch (Elizabeth Olsen) volunteers to help the Avengers stop an out-of-control train. Another Marvel compatriot, Spider-Man, had to pull off a similar stunt in his 2004 movie.

6. Meet Tony Stark’s New Female Interface, Friday
After Jarvis jumps the 'net and becomes Vision (Paul Bettany), there’s “His Girl Friday” to help Stark (Robert Downey Jr.) co-pilot his Iron Man suit. “His Girl Friday” director Howard Hawks’ influence can also be heard in Whedon’s devotion to snappy dialogue.

7. The heart-ripping scene from “Indiana Jones and the Temple of Doom”
Well, there’s more than way to break a heart. Scarlet Witch does her best “Temple of Doom” impression to show Ultron how much it hurt to feel her brother Quicksilver (Aaron Taylor-Johnson) killed.  

8. Tony Stark rocks a T-shirt featuring Bruce Lee
Robert Downey Jr. is a big Bruce Lee fan and frequently wears T-shirts with the legendary actor’s likeness. The actor sports a Lee shirt in “Avengers: Age of Ultron.” Downey even held an opening weekend giveaway with the company that creates the shirts, Bow and Arrow 78.