I just searched for "frog party" on YouTube on the vague assumption that because frogs are so chill that they must indeed get down with amphibian fiestas. Well hoo boy, do they ever. This video shows a whole bunch of gliding leaf frogs chilling near some water in a mating frenzy.
Aside from the eggs and the obvious fornication going on, it's clear the frogs are mating because normally they hang out in trees. They're in the sub-family Phyllomedusinae, a group commonly known as leaf frogs, and which is part of the greater tree frog family Hylidae. That means the froggies above generally spend all their time in the forest canopy. But when it's time to produce more gliding leaf frogs, they all come down en masse to water sources to mix genes and lay their eggs, before going back on their merry way.
According to the video description, these frogs were filmed in Corcovado National Park in Costa Rica, where once upon a time I actually happened to briefly live, although then I was more interested in butterflies than cool-ass frogs. It's not rare to encounter tree frogs in general, but gliding leaf frogs are rare, and seeing so many in one place is even rarer. They get their common name from a curious method of escape they have at their disposal: If they need to get somewhere in a hurry, they can drop off a tree, and use the wide webbing between their feet to slow their descent. Pretty cool, right?