peeny-wally
/ˈpiːnɪˌwɒli/Caribbean (especially Jamaican )
noun
A firefly; specifically a luminescent click beetle (family Elateridae), especially of the largest Jamaican species, Pyrophorus plagiophthalmus.
Origin
1960s. Origin uncertain; perhaps humorous blend of Carribean English peeny very small, tiny, and peely-wally.