I see this snail, what should I do?

Hint 1 of 4:

Make sure you have the horn, it is found on this level.

Hint 2 of 4:

This guy is an informant, just like Dragnet.

Hint 3 of 4:

Sgt. Friday, usually paid informants.

Hint 4 of 4:

Pay the snail 36 coins, you should have EXACTLY that many, There is
only 36 coins in the game.