Most places that carry the Zoom Horny Toad have the hooks, right next to the toads, that you are supposed to use with the Toads. I believe that they are 5/0 hooks.
Everyone that I have ever heard discussing them have screwed the hook onto the bait, and rigged it so that the hook came up through the back, with no skin hooking needed. This keeps it weedless, and when a bass blows up on it, it allows for a better chance of hooking up. Of course, you have to be patient and wait to feel the fish on the lure before setting the hook.