Other than serious roles like in Mullum Malarum, in the comedy roles we have -

Netrikann - the older dad Rajini dominated the movie. Great entertainment all the way! The younger son was just playing his role, not much to report there.

Thillu-mullu - both characters were superbly enacted by Rajini along with excellent supporting roles by Poornam V, Theanga S. and Sowcar J.

Both of these gems were by KB sir.

His comedy handling for the first time in his career in these films proved his ability to handle that genre with ease. So, there's a variety of genre types he can handle. It depends on his mindset to take on varied roles with other directors.