All species of harlequin frogs are named for their bright colors, which are reminiscent of the colorful costumes worn by harlequins in literature and pop-culture. The variable harlequin is usually a shade of yellow or orange with dark markings; the bright colors may prove as a warning to predators of their toxicity. These frogs are poor swimmers, rarely entering streams and relying on splashes for their moisture; they only enter the water for breeding season. The only known predator of the variable harlequin is a species of fly that lays its eggs on the frog's thigh. The fly larvae then burrow into the frog, eventually killing it.
The variable harlequin population is critically endangered in both Panama and Costa Rica. In Costa Rica, experts believed the frog to be extinct until a population was found in 2005; currently, the species is thought to be extinct in Panama. Much of its decline can be attributed to the chytrid fungus.