Smashboards

I'd make it so it's inside of a pool of water while on the ground, with the front half of its body poking out normally and only having the fin visible while crouching. It'd be able to crawl, naturally.

Since the shark needs to be mobile, I’d have it surf on a small current of water while sliding on its belly when it dashes on land. You could have it flop around awkwardly while “walking” to still have that funny animation.

(Alternatively you could have it travel underground with the fin sticking out, but having so much of its hurtbox retract might be frustrating to fight against.)

Move around the air as if it was water and care not a bit for things making sense

Obviously you just see the fin like in jaws until you attack!

Ooo good idea. MBRRedboy

I'm imagining the fin sticking out thing could be like, a greninja style teleport of all things