"Eleven is growing up and I think that's the terrifying thing for Hopper. He doesn't like the idea of his baby daughter hanging out with boys. So the season starts with him a little bit uncomfortable.

"His daughter is becoming a teenager and beginning to find herself, so that's scarier for Hopper than any Demogorgon creature that he's going to have to deal with," Harbour said at MCM Comic-Con The actor teased that the episode eight of the new season is something to look out for.

"You get to see a lot of that throughout the season and it's very unexpected what happens in the end and it's very, very moving. I think episode eight is the most moving thing we've ever shot," he said.

"Stranger Things 3" will launch on Netflix on July 4.