We may earn a commission from links on this page. Undertale, the Steam RPG hit where you don’t have to kill anyone, is loaded with secrets. Dedicated players have unearthed every last one... well, ...

Asriel Dreemurr is the true final boss of Undertale, coming after you've explored the bonus True Laboratory section. The following boss comes at the end of a complete Pacifist playthrough - in short, ...