SCP-0021:The Undertale(Megalonavia)

The SCP-0021(Undertale) was not known until Megalonavia Creator Toby Fox came fleeing into our Foundation and reported that he saw his creations come to life.
SCP-0021 was a completely accurate remodel of the game Megalonavia: buildings, beings, materials, all exactly the same as Toby Fox designed it to be.
And here, things get nasty.