The Bugsnax ending explained is a task that will require one to first sit down and take a sip of water.
Here is our explanation to the unexpected ending of Bugsnax. Full spoilers ahead of course.
Bugsnax Ending Explained
After completing the quests to reunite all of the Grumpuses, the people of Snaxburg throw a harmless dance party. Unfortunately, the festivities are quickly cut short by an earthquake and a volcano eruption.
While the rest of Snaxberg prepares to escape the island, the player, Eggabell and Filbo decide to try to find and save the long-lost Elizabert Megafig from a sealed-up mountainside cavern. Thankfully the door which previously refused to open gives way to the trio, but merely provides a brief moment of hope as the three fall through the ground upon entering.
Soon enough, they find Megafig in what appears to be a courtroom with an audience of Bugsnax on both sides.
Megafig is no longer a Grumpus, but has been transformed against her will into something past the point of no return. The Bugsnax, once thought to be a harmless species for travelers to eat, turn out instead to be a hive-like mind of parasites not only looking to takeover others' bodies, but also composing Snaktooth Island as well.
"They’re parasites," Megafig says. “They get inside you and they ... change you. Your body and your mind. They make you want them, and before you know it, you become them.”
Megafig then urges the trio to leave as the island will soon be destroyed. While Eggabell decides to stay behind with Megafig, the player and Filbo decide to escape with the truth about the Bugsnax.
At this point it is up to the player to determine their ending as once they returned to Snaxburg, they'll have to fight off the Bugsnax, losing as little of the Grumpuses as possible. The main differences between the two endings is the mood of the reflection scene on the beach once everyone's escaped, as well as a post-credits scene.
Feel free to check out JustALazyGamer's video to hear the strange dialogue suggesting the player's editor knew the dark secrets of the island beforehand.