Dont Starve Together Don't Starve Together

This guide detailed explains events which named Full Moons.

Full Moons Guide

This is a quick guide on full moons, including when the first few full moons will be, and what can and will occur during them.

Full moons are very important events. Here are some of the most important things to remember about them.

Most Important Things

During full moons, everything will be clearly illuminated (at night) and you will not need to worry about the darkness attacking you.
Any pigs caught outside during a full moon will transform into aggressive were-pigs.
Full moons are your only opportunities to collect glommer's flower (which is the item to control the location of glommer, who will spawn after the flower appears) from glommer's statue.
Aggressive ghosts will emerge from any type of grave during a full moon.

Other Things

Woodie will transform into a werebeaver during a full moon.
Chester can transform into Shadow Chester or Snow Chester if the right conditions are met during a full moon.
Wild and aggressive pigs (wild boars?) will also turn into were-pigs when caught outside during a full moon.
Tides (in beach biomes) are much stronger during full moons.

The first full moon will happen on Night 11.

After the first full moon, one will occur every 20 days.

Source: https://gameplay.tips/guides/6223-dont-starve-together.html