Undertale AU Sans x Reader Oneshots

Nightmare! Sans x Child! Reader (Short story...sort of)

(This happens before he went into his gooey form).

Nightmare's POV
I don't understand why I have to be here. I never asked to be this way or to be born. Don't get me wrong I love my brother but he sometimes ticks me off. Everyone loves him and not me because of my job. I am at home eating pancakes. After like a few minutes someone knocks at the door. I'm pretty sure no one knows where we live so it must be Dream. I get up and head towards the door. "Dream yo-" There was no one there. What? The sound of small snores can be heard below me. I look down to see a small human baby covered in a blue/pink blanket. Who would leave their baby here and how did they find our house. I pick up the basket and see a note.

To whom it may concern,

I'm so sorry to give you such a responsibility. I love my little baby but I can't take care of her/him. So please do me a favor and take good care of (Y/N). The only thing I want is for my little baby to be happy but that won't happen if she/he is with me.

                                   ~Joan

Must be a loving mother if she does this. (Y/N) starts to wake up and giggle. I smile as I hold their small squishy hand. "Let's get you inside." I get back inside the house and close the door. What a precious kid just looking at them can make anyone's heart melt away. (Y/N) holds onto my my index finger and starts to smile at me. I'm already getting attached to them. The door opens to reveal Dream. "I'm home!" He yells out as I shush. He turns around and starts to squeal silently just from one glance. He skips towards me and sits next to me looking at (Y/N) with much happiness. "So cute. Why do you have a human baby with you?" He looks at me as the baby plays with our fingers. I grab the letter and hand it to him. "Some woman named, Joan, left them here saying she can't take care of (Y/N)." He skims through the letter. Once he was done he places it down at the couch and then suddenly raises a brow. He looks at me and then (Y/N). "(Y/N)," he asks if that was their name to which I nod. He smiles warmly and plays with their arms. "It suits her/him well." We both enjoyed that day since (Y/N) was in it.

The next day I went baby shopping to get things that babies need. I buy clothes, shoes, diapers, all kinds of stuff for (Y/N). I then head home where Dream is taking care of them. When I enter the house Dream was dancing with (Y/N). Seeing that just made me smile and forget all the jealousy. "I got the stuff." Dream turns around with a bright smile that shines like the sun. Guess he has been having fun with little (Y/N).

Dream and I went to the tree to guard it so no one steals the fruit. Although Dream did all the work I was behind the tree taking care of (Y/N). She/he is a calm baby but is a handful, always wants attention. I started to give her/him their formula. Man we haven't even had (Y/N) for a week and they are already changing our lives. She/he brings more happiness into our lives especially mine. At first I thought no one loved me except for Dream but turns out that someone else loves me too even if they can't talk and isn't fully developed. I started to hum to (Y/N) so they can go to sleep which worked after a minute humming and rocking her a bit. This has just turned into one of the best days that I have ever had. I look up to see the beautiful scenery behind the tree. Just a whole field full of nice tall green grass, flowers, and a few trees swaying with the wind's song. This day is just so amazing that nothing can ruin it.

8 years later

"Hey dad look I made you a flower crown." I turn around to see (Y/N) running towards me with a flower crown made out of buttercups. (Boy outfit: F/C t, F/C shorts. Girl outfit: F/C dress). A smile spreads on my face as I kneel down to pick up (Y/N). She/he giggles and puts the crown on me. O already have a crown but I like this one better. "Thank you (Y/N). I love it a lot." I hug her/him as they hug me back. I kneel down again so they can run around and be energetic. They ran around and fell on the buttercups as they just stare at the clouds. I smile but it faded away as I look back at the tree. Mine are just as good right? My legs start to move to the tree as I take a bite out of the black apple. After a few moments everything started to hurt and one of my eye sockets started to get covered up by something. My vision started to blur as negative thoughts started to enter my head. I fall to the ground in pain.