The Musical Fiddler Crab
Fiddler crabs look like they're playing a musical instrument, and are among the most effective live baits there are.
This article is from North Carolina, but if you fish in Florida - particularly around the west central coast of the state - you know about fiddler crabs. One of the absolute best and most effective baits for Permit and Pompano at the area's bridges, they're equally productive fishing for redfish or pretty much anything in the water that bottom feeds.
Here's a few words about the beautiful little crab from the article on the Carteret County News and Times:
Fiddlers are found along with mud snails and among the muddy edges of the Spartina grasses in the intertidal marshes of our sounds. They hide deep in their burrows on the rising tides and return upward to the marsh’s mud flats on the receding tides.
The whole story is here on the paper's web site.