Undertale x Child!Reader Scenarios

First Words (Adult!MK x Quiet!ChildReader)

Quick Author's Note: "Monster Kid" will be called Monster Guy in this oneshot because he is obviously no longer a kid.

Monster Guy's interaction with the human Frisk many years ago, coupled with moving aboveground later where there were even more humans, inspired him to eventually adopt a human child for his own.

His heart was immediately taken by a little kid at a human orphanage named (Y/N).

Upon hearing his choice, however, the caretaker of the orphanage looked a lot more sad than when the monster came in.

"(Y/N) is a nice kid... but they're kind of reclusive. They don't talk at all, and..."

"Are they mute?" Monster Guy inquired.

The caretaker folded her hands. "It's hard to tell for certain. But they haven't even attempted socializing with the other kids. We don't know what happened to them before they came here that could have caused this, but—"

"I'll take 'em."

You arrived at your new home, Monster Guy's apartment, later that day. You brought your sparse belongings in a little backpack, which your new father offered to carry for you. When you gave no answer, he just moved on from it and opened his door.

The apartment wasn't that big, but it was nice. A basic kitchen stood off to your immediate right, and the living room with a couch and a small television was in front of a huge window that allowed you to look down at the two levels below you.

To the left of the living room was a door that presumably led to your monster dad's room. Speaking of him, he walked over and smiled at you warmly before crouching down to meet your eye level.

"So (Y/N), how do you like it?" He asked.

You gave a little nod and shrugged at the same time. You fully expected him to ask what you meant, tell you to give a verbal answer, any of the things everyone else did when you didn't speak.

But he didn't. He just grinned and responded, "Aw, I'm sure you'll learn to love it! If you want something to eat just give me a tug on the shirt, okay? I gotta do some work on the computer now..."

He looked down at his total lack of arms and laughed. "I know. I just use my tail to work the computer!" With that, he disappeared into his room.

Over the next few weeks, you noticed how different this monster was from all the humans in your life. Whenever you didn't give a verbal response to something, he just adjusted his question so you could nod or shake your head. He made jokes whenever you seemed down. He never got angry with you for not talking, but instead was patient and tried his best to understand you. He homeschooled you and taught you to write with a pen in your mouth.

He was the best parent you could ever hope for.

Almost a year after being adopted, you went up to your monster father while he was trying to make sandwiches for you and himself and tapped his back.

"Yo! What's up, sport?"

You took a deep breath. For months you had been preparing to give him the ultimate thanks for his dedication. Now you were ready.

You cleared your throat.

"Th-thank you... Dad."

The monster dropped the butterknife in his mouth and turned to you, eyes wide.

"(Y/N)..."

"Thanks... for helping... me," you said slowly.

Your father's eyes started to well up with tears of happiness.

"Yeah... no problem kiddo."