Harbour was worried about an influx in fan theories that would explode across the internet because his “Stranger Things” character, Hopper, was last scene in a Russian prison, while his Marvel character in “Black Widow” is “a guy who starts out in a Russian prison.” Harbour knew the internet would have a field day connecting these characters, which is not what he wanted. It then became Harbour’s top priority to ensure nothing about the look of his Marvel character or setting matched his “Stranger Things” character or setting.

“I was taking pictures of the set unbeknownst to anyone and sending them to the Duffer Brothers making sure they didn’t use any of the same colors as the [‘Black Widow’] set,” Harbour said. “And making sure the looks were different and the outfits were different. I kept sending these photos.” “I had this long hair and this beard and I was big and I thought, ‘I can’t be the same guy with long hair and a beard in the same prison,” Harbour added, which led to the decision to shave his hair so that Hopper appears bald in “Stranger Things 4. “I was like ‘guys, we can’t do this. I mean, I’m coming out with this Marvel movie, I can’t have the beard and the hair.’ So we came up with a whole different look for it.” Despite Harbour’s best efforts to prevent crossover theories, such conspiracies took off regardless. The actor came forward last summer to downplay any theories predicting a crossover between “Black Widow” and “Stranger Things 4.” “I know, it is a very surprising, annoying coincidence, and I apologize to the entire internet,” Harbour said last year about the Russian connection between his MCU character Red Guardian and Hopper. “There is no rhyme or reason for it, I promise you. There’s no crossover event between ‘Stranger Things’ and the MCU. I mean, I do look very different in them. One of them, I’m 270 pounds and got a beard and thick, long hair, and the other one I’m like 200 pounds and have no hair.” “Black Widow” is opening in theaters and Disney+ on July 9. “Stranger Things 4” does not yet have a release date from Netflix. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.