Nothing says they have to big BIG frogs? A lot of small frog popper patterns are not much bigger than some Hopper patterns.

By the way since I read here about cutting foam plugs out of flip flops, I have been looking for cheap flops to do this with. I was at WallyWorld last night and saw a pair of green 'high-heel flops' like you mentioned with a good 1.5 inch think 'heels'. Yep you're definitely on to something with this whole plug cutter, flip flop idea.