Apoorva Sagodarargal (1989)
Much has been said and written about this classic movie directed by Singeetham Srinivasa Rao, starring Haasan in three dynamically different roles.
As the murdered father Sedhupathy he was properly aggressive, twirling his moustache with gusto. As the normal half of the twins, Raja, he was up to his usual antics. But it was his transformation as the slightly neurotic other half, Appu, that shocked everyone who saw him.
To pass off as a midget, Kamal had to walk on his knees, a torturous technique which involved getting his legs tied up behind his back.
Some facial expressions brought the character to life, one of them was baring his teeth a fraction more than normal.
Also Read: Playing Kamal Haasan's love interest