I find that Mandibuzz really needs Toxic, since it can't directly counter anything otherwise. One of Mandibuzz's best qualities is its great bulk which allows it to check Moltres, Slowking, Sceptile, Rotom-C and other special attackers. However, it can't touch any of them except for Sceptile if it lacks Toxic, and it's just asking for a crit or a burn. I think that Brave Bird and Taunt are the two moves that can be replacable on the set. Taunt is better against stall, making it a good stallbreaker, but Brave Bird is more useful against offense, and allows it to be a quick answer to Lilligant.