knowledge - Who's this Pokemon?

The requested Pokemon belongs to the original ones, often called the real ones, i.e. the first 151 Pokemon.

1. I do what I know best, but people don't appreciate it!


2. This makes me feel bad, I punish them!

_{More clues upon request, I guess :)}

Answer

You are

Jigglypuff, based on the cartoon where she draws on people's faces when they fall asleep after hearing her sing