Tom Haverford DnD Character

I'm trying to build a character centered around his baby whining when he's trying to convince someone or something, the really pathetic kind.

Can someone help me build this guy? I can act it out fine but mechanically I didn't know how to make it work.

I'm thinking combat-wise I'll be cowering and then knife them when they think I'm not worth killing because I'm so pathetic, almost a Ric Flair combat style.