... the guy who played Alexander is covered in tattoos, looks like a junkie, and was arrested a couple times for a DUI and assault twice.
Child actor gone bad? Thankfully this almost never happens.
Tng: Reggie - (he's the imperfect Starfleet officer)
Ds9: Dabo girl Leeta
Voy: Naomi Wildman - (God but she grew up hot)
Ent: The crash test dummy they duct-taped to the helmsman's chair