My team is based on cryptids.

The gym would be a spooky forest, with traps that lead to trainers. The trainers in the gym would have dunsparces, magnemites, baltoys, phantump, and dittos. You could avoid the traps/trainers if you have a map (which I would give the PC if they explored the local cave and got to the end of it, they of course are unaware I am the local gym leader). At the end of the gym, the forest breaks, and you see me behind a small campfire ready to battle.

Also the badge is abomasnow's footprint