I watched Exo SHOWTIME ep 10 and realised that the most cowardly member in Exo is Tao, even though he knows martial arts. it's actually really cute to see him so afraid of ghosts and bugs ^__^. In EXO-K i think it's Baekhyun and D.O. who are the most cowardly (this too is based on Exo SHOWTIME )
When I was watching Exo Showtime (the part where they filmed the haunted house and their reactions inside), I was thinking that maybe it's Baekhyun in EXO-K and Tao in EXO-M ^^