How do i make my own sprites that can be used in Whacked2? for enimies and stuff

Hey, I'm making a wad for Doom 2 with Doom Builder and Whacked2. I wanted to know how (if there's a way) to basically make my own enemies? how do i get the sprites into whacked and what not?

Please help thanks

http://www.doomworld.com/vb/doom-editing/46588-adding-custom-monsters-in-doom-builder/

Unfortunately that thread didn't answer my questions to the full extent but they did give me ideas so I replied to that thread. If you read this could you please go to that thread to help me out :) thanks