Such as weight gain/loss, height, change in hairstyle, facial hair, cosmetic surgery, etc.

There are two that come to mind. The first was Michael Gross on Family Ties. In the first season, he was clean shaven. From the second season on, he had a beard. The second was Jackie Gleason in the last season of the Color Honeymooners. He lost a lot of weight after he went on a diet.

The first was Michael Gross on Family Ties. In the first season, he was clean shaven. From the second season on, he had a beard.Jonathan Frakes on Star Trek: the Next Generation was the same way.

David Soul in the final year of Starsky & Hutch.

Years ago when I was watching S&H, I initially thought there was a new Hutch in the fourth & final year.

The entire male cast of The Brady Bunch. One season, they were clean cut and middle American, and the next season rocking curly perms, bellbottoms and polyester disco shirts! :happyface

Dwayne Hickman (Dobie Gillis). Bleached his hair, then wore his naturally dark hair because he said his hair was falling out! :confused:

Sally Struthers went from having the Shirley Temple look (short curly hair) to super straight hair.

Amanda Bearse (Married with Children) started out with a feminine Yuppie look, then cut her hair and looked more "butch" in hair and clothing.

Joyce DeWitt went from having short curly hair and having a tomboy look to the movie star, more feminine look of Lisa Minnelli.

Elizabeth Montgomery changed dramatically three times. First, she had the more conservative Camelot look (gloves, purse and shift dresses), then more dressed down/ beatnik (sweatshirt and jeans) and later the ultra-mod look (go go boots, psychedelic minidresses).

Someone mentioned Star Trek, and I think that series wins hands down in terms of dramatic changes. Jennifer Lien (Kes from Voyager) went from wearing a short pixie haircut and minidresses in one season to a long blonde wig and catsuit the next. Avery Brooks (Sisko, ST9) went from having hair and no beard to vice versa (bald with beard).

Between the first and second seasons of The Facts of Life, Charlotte Rae went on a very stringent diet and at the start of the second season had lost an enormous amount of weight.

Henry Winkler had a fully grown beard at the beginning of the eighth season of Happy Days. He had vacationed in Italy in the summer of 1980.

Michael Lembeck had a beard for three seasons before he was clean shaven for the final season of One Day at a Time.

:lembeck2: :lembeck:

Who had the best beard on a sitcom? (https://www.sitcomsonline.com/boards/showthread.php?t=417988)

3rd Rock from the Sun: Joseph Gordon-Levitt as Tommy Solomon had his long hair cut into a short style late in the series.

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His character even commented on the change.

Felicity: Series star Keri Russell's haircut was a very dramatic and much-discussed change:

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Friends: The Tragic Reason Behind Chandler's Season 7 Transformation Explained (https://www.looper.com/1348794/friends-tragic-reason-behind-chandler-season-7-weight-loss-explained/)

There's a tragic reason behind Chandler's sudden Season 7 transformation in "Friends" and it's made all the more apparent by the use of the exact same attire.

The entire male cast of The Brady Bunch. One season, they were clean cut and middle American, and the next season rocking curly perms, bellbottoms and polyester disco shirts! :happyface

Dwayne Hickman (Dobie Gillis). Bleached his hair, then wore his naturally dark hair because he said his hair was falling out! :confused:

Sally Struthers went from having the Shirley Temple look (short curly hair) to super straight hair.

Amanda Bearse (Married with Children) started out with a feminine Yuppie look, then cut her hair and looked more "butch" in hair and clothing.

Joyce DeWitt went from having short curly hair and having a tomboy look to the movie star, more feminine look of Lisa Minnelli.

Elizabeth Montgomery changed dramatically three times. First, she had the more conservative Camelot look (gloves, purse and shift dresses), then more dressed down/ beatnik (sweatshirt and jeans) and later the ultra-mod look (go go boots, psychedelic minidresses).

Someone mentioned Star Trek, and I think that series wins hands down in terms of dramatic changes. Jennifer Lien (Kes from Voyager) went from wearing a short pixie haircut and minidresses in one season to a long blonde wig and catsuit the next. Avery Brooks (Sisko, ST9) went from having hair and no beard to vice versa (bald with beard).

No, that was Jennifer Lien's real hair. The producers let her grow it out so she could cover her ears, I just read this somewhere earlier this year. It was so she didn't have to wear the pointy prosthetic ears anymore, because she was apparently allergic to some adhesive they'd use to hold them in place on her actual ears and she got a bad itchy rash because of it. So she asked if she could stop wearing the fake ear parts and grow out her hair so her ears were hidden, and they agreed to it.

Ed.

Probably not quite so dramatic. But when Mike Farrell, who played B.J. Hunnicutt on M.A.S.H. first joined the show he was clean shaven. But he later grew a moustache which he kept for the rest of the show's run.

Ed.

Roseanne Barr on Roseanne. So many different hairstyles/colors, weight gain/loss, cosmetic surgery.

The morphing intro from the later seasons showcases Roseanne change of appearance throughout the seasons.

No, that was Jennifer Lien's real hair. The producers let her grow it out so she could cover her ears, I just read this somewhere earlier this year. It was so she didn't have to wear the pointy prosthetic ears anymore, because she was apparently allergic to some adhesive they'd use to hold them in place on her actual ears and she got a bad itchy rash because of it. So she asked if she could stop wearing the fake ear parts and grow out her hair so her ears were hidden, and they agreed to it.

Ed.

Actually, this always has been a topic of debate among Voyager fans. Lien did have blonde hair in real life, but it had a different texture and color than what was on the show, so this is why people concluded that it was a wig.

The entire male cast of The Brady Bunch. One season, they were clean cut and middle American, and the next season rocking curly perms, bellbottoms and polyester disco shirts! :happyface

Dwayne Hickman (Dobie Gillis). Bleached his hair, then wore his naturally dark hair because he said his hair was falling out! :confused:

Sally Struthers went from having the Shirley Temple look (short curly hair) to super straight hair.

Amanda Bearse (Married with Children) started out with a feminine Yuppie look, then cut her hair and looked more "butch" in hair and clothing.

Joyce DeWitt went from having short curly hair and having a tomboy look to the movie star, more feminine look of Lisa Minnelli.

Elizabeth Montgomery changed dramatically three times. First, she had the more conservative Camelot look (gloves, purse and shift dresses), then more dressed down/ beatnik (sweatshirt and jeans) and later the ultra-mod look (go go boots, psychedelic minidresses).

Someone mentioned Star Trek, and I think that series wins hands down in terms of dramatic changes. Jennifer Lien (Kes from Voyager) went from wearing a short pixie haircut and minidresses in one season to a long blonde wig and catsuit the next. Avery Brooks (Sisko, ST9) went from having hair and no beard to vice versa (bald with beard).

Avery Brooks was clean-shaven and had a full-head of hair during the early years of Star Trek: Deep Space Nine, because at the time, he was still very closely identified as being Hawk on Spencer for Hire and its subsequent spin-off, A Man Called Hawk and he understandably, wanted to show people that he could do other things as an actor.