do-gooder

When they thought about Lewis, what struck the players most was that he never acted like a do-gooder.

NSA whistleblower Edward Snowden may just be a naive do-gooder in over his head.

She appears to be the perfectly pleasant, party-planning, sociable do-gooder.

To hear her speak is to hear that passion combined with the heart of a do-gooder and the simplicity of a child.

Leigh Anne may dress (and decorate) tackily, but she is unquestionably a strong-minded and moral do-gooder.

You know, I often attach myself to the elderly do-gooder type like my father was.