I do not own Harry Potter (its J.K. Rowlings) or Rocky Horror (thats Richard O'Briens), I only wished I did. If I did then nobody would have died in last HP book (sob) and Magenta would have a bigger part in RHPS
A cross over between RHPS and HP! Sigh
Frank – Snape (black hair)
Rocky – Draco (blonde hair)
Brad – Harry (glasses)
Janet – Ginny (because she loves Harry)
Riff Raff – Ron (who knows?)
Magenta – Hermione (bushy hair, and Ron would probably still love her even they were siblings)
Columbia – Luna (they're both pretty giddy)
Eddie – Hargid (fat)
Dr. Scott – Dumbledore (professor)
The Crim & Lips – The sorting hat (because it tells stories)
Transylvanians – All the rest of the Weasley's (theres enough)