Wollowan

The Wollowans were a frog-like species known to the Federation by the 24th century. A Wollowan boy attended Keiko O'Brien's school on Deep Space 9 in 2370, when a baby Horta burrowed into the class the boy panicked and jumped, almost hitting the ceiling. (DS9 novel: Devil in the Sky)
 * The Wollowans were likely a species native the alpha or beta quadrants, though it's possible they were visiting gamma quadrant natives.