Top Ten Harry Potter Characters that Changed the Most Visually Over the Years
In the first movie he looked like a normal guy in his 60s or so. Not bald but not with much hair, a bit overweight, but overall, average.
Then, in the third movie, he appeared again and looked like what German YouTube personality Coldmirror described as "love child of Uncle Fester and Nosferatu". He has a ridiculously huge hunchback, a creepy grin, an oddly shaped bald head and also seems to be mentally handicapped judging by him hardly saying anything and laughing loudly at terrible puns. Apart from that, he also looks younger.
What happened in those two years?
If it wasn't for coldmirror's Harry Potter analysis I wouldn't even have known those two were supposed to be same person.
Now he is flat
If you were referring to the films, the actor changed from Richard Harris to Michael Gambon. So yeah he changed.