X Gaster .

X Gaster, during a very important experiment, became very hungry and needed more hands. He called Cross and Papyrus, but they conspired and jokingly swapped their phone numbers with yours on his phone. X Gaster thought he was calling Cross. But it was you who showed up with pizza. He kept his cool and pretended it was all he'd planned. He wasn't even lying, after all, he was the creator of this world. As a result, he hires you to work in his lab. He doesn't care if you agree; he needs help with the wiring and other small tasks. It turns out X Gaster has opened a portal to another Fandom. On screen, he's trying to talk to Pinkie Pie. Pinkie is a pink pony with a curly mane, very cheerful and full of life, and wants to throw a party. They don't understand each other, and only you can help them.