9 things you probably didn't know about the making of season 3 of 'The Boys'

Theron pops up in the opening scene, replacing the real Stormfront (played by Aya Cash) for their supe film "Dawn of the Seven."

"The Boys" showrunner Eric Kripke told Entertainment Weekly that Theron filmed her appearance in Simi Valley, California for a full-day shoot.

Meanwhile, Antony Starr (Homelander) and the rest of the "Boys" cast and crew filmed separately in Toronto, Canada.

"You'd never tell when you see it cut together," Starr said. "It's hysterical, the whole setup."

"Even though it was very much sweetened by the effects, that is a practical penis," Kripke told Variety. "That is an 11-foot high, 20-foot long penis head that has a urethra, a tunnel in it, and built at great expense. We got Sony and Amazon to pay so much money to build this set. And it's just another reason why I love my job."

Termite actor Brett Geddes also shared a behind-the-scenes look at him and his stunt double, Alex Armbruster, standing by the large prosthetic piece.

Stormfront was severely injured during the season two finale, but Cash briefly reprised the role in season three. Her transformation required sitting in a hair and makeup trailer as various prosthetics were applied to her face.

Starr shared behind-the-scenes photos of Cash's prosthetics and said that she gifted it to him.

Early in episode three, Hughie asks Kimiko (Karen Fukuhara) to break his arm so he can call out sick for a few days to work with the Boys and avoid raising suspicions at work.

In actuality, a realistic arm was strapped to Quaid so he didn't get injured. The actor also rehearsed the scene, to ensure that his character's reaction would be believable.

After rejoining The Seven, Homelander presents The Deep (Chace Crawford) with a live octopus to eat in episode three. Because Timothy is Deep's friend and he can communicate with the sea creature because of his powers, Deep is reluctant. But he unwillingly consumes Timothy.

The octopus was CGI, and Crawford told Entertainment Weekly that he had to eat mochi, syrup, and another ingredient for the scene.

"It was disgusting," he said. "But yeah, it was palatable. It was OK."

In another interview with Collider, Crawford said he had chopsticks and "a mochi ball, or something like that, with some syrup mixed with chocolate."

Vomiting is one of the side effects that Butcher experiences as a result of injecting himself with temporary compound V. Just as he and Hughie are having a serious, heart-to-heart moment in episode three, Butcher ruins it by spewing green-colored vomit on Hughie's face.

According to Prime Video's X-Ray feature, the show's special-effects team handled a pump on the other side of Urban, which sprayed Quaid.

Quaid said that the green liquid "tastes a lot less disgusting than it looks."

The body cast was covered in the supe costume and a crushed skull piece was placed on top of it, per Prime Video's X-Ray trivia.

Kimiko sings "Dream a Little Dream" during a fantasy scene in the season one premiere. Later in the season, while in the hospital, she daydreams and performs Judy Garland's "I Got Rhythm" with Frenchie (Tomer Capone).

"I grew up taking singing lessons in high school and middle school," Fukuhara told Variety. "In college, I was part of an a capella group. I love singing, I just have terrible, crippling stage fright when it comes to singing in front of a group of people."

It took one day to film the musical sequence, and Fukuhara told Insider that she "never would've thought my character would partake in any of those things."

"All the rehearsals that went into it and just listening to the music, practicing the song and everything, it was an experience that I have never had before," the actress said. "It was a challenge, but it was a lot of fun."

After taking temporary compound V, Hughie gains the power to teleport — but every time he does so, he ends up naked.

During an appearance on NBC's "Late Night With Seth Meyers," Quaid said that the modesty clothing "may actually be worse than being naked" because of how embarrassing it is to wear.