Between the third and fourth seasons of “Stranger Things,” David Harbour lost a lot of weight, and he recently posted fresh pictures showing the process.

Harbour, 47, announced he lost 75 pounds between the two seasons of the popular Netflix series in a post on Instagram on Thursday.

Harbour posted a collection of images with, “Many of you have asked about Hopper’s physical shift from season 3 to season 4.” For eight months [sic] to achieve the change and another year to maintain it throughout the epidemic, my trainer @davidhigginslondon worked with me. “Changing diet and exercise programs (or lack thereof)” is “a difficult and exciting ride,” according to Harbour.

What are those new photos documenting David Harbour weight loss journey?

The opening image in Harbour’s article is a mashup of his character Hopper in season 3 (top) and season 4 (bottom) (bottom). The second image is of Harbour and his trainer just after they started working out, with “my resistances and rage flashing,” as the actor put it. The third and last image was taken on the day he was filming a shirtless scene for season 4. Black “x” marks have been placed to his torso, which he claims were done so “for cgi scarring due to issues with the practical effect.”

“In total, I shed over 75 pounds. Harbour noted that he “just swelled up again to play jolly ole st. Nick in a movie I can’t wait for you to see this Christmas season. I was 265-270 in season 3 and all the way down to 190 when we shot. Harbour will play a violent Santa Claus in the movie “Violent Night.” Nevertheless, he claimed that now that production on the project has ended, he is “struggling to battle back down towards a good weight for wherever [H]opper ends up in season 5.”

On Friday at 4 PM U.K. time, Harbour and his trainer David Higgins will conduct an Instagram live. Harbour stated, “I want to address any questions you may have with @davidhigginslondon and tell you what I learned.”

In an interview with GQ Hype earlier this month, Harbour talked about altering his physicality for roles. He told the fashion magazine, “I don’t think I’ll ever do that again.” “I gained [it all back] because I have this Santa Claus movie coming out for Universal in December.” But as of right now, never again. The artificial limbs are too good.

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