I like that character idea! So long as the rest of the party's on board with a character that doesn't contribute in combat, it offers a really cool option for roleplaying.
Last week my group was short of players, down to four instead of our usual six. Despite that, our intrepid guardsmen managed to pull a fast one on Bruce 'Sharky' Sharpe, the local supplier of 'green death,' the latest narcotic on the streets. Sharky was selling this dangerous substance in the city's slums, but given how cheap and addictive it is, the group's mission was to discover the source of this substance to ensure it didn't spread into the rest of the city and cause a crime wave after the addicts unerringly turned psychopathically violent.
The group managed to track down Sharky, disguise themselves as addicts, and convince Sharky they were defending him by dressing up a few local criminals in their own city guard outfits and executing them in front of Sharky (courtesy of our chaotic evil rogue).
They'd previously learned that Sharky was a natural lycanthrope, specifically a were-shark, and one tough customer in a fight. Given the group was all level one, a well placed blow could probably kill any of them in one round, so they used a remarkably rare show of insight in setting an ambush. The evil rogue gained Sharky's trust, being given the honor of accompanying him to visit the gnome who manufactured the drugs in his Breaking Bad style cookhouse down in the city's sewers. After returning, the group ambushed Sharky, and the defeat was a remarkable victory for all involved, especially given the mini-boss was balanced for their full party of six players.
Still, I'm sad I won't be able to bring back Sharky's horrible Australian outback accent again. He was a hell of a lot of fun to portray.