Hi, I found a bug with Designer Frightfur. The monster special summoned by its effect is not treated as a Frightfur monster when used as a fusion material. This happened in YGOPro Android 1.4.7, but YGOPro1.033.6 may have the same problem.

EDIT: I just realized that it's not a bug, since Frightfur Sabre Tiger requires a Frightfur fusion monster, that's why Designer Frightfur was useless. My bad.