It was a normal day in Hotland. Well, as normal as a day in the Underground can be, anyways.

Every monster in the place was going about their daily lives, all except one.

His name was Sans the Skeleton, he wore a blue hoodie, black shorts, a white top and slippers, and was known by many for being lazy and telling jokes to keep their spirits up.

Right now he sat at his sentry post in scorching Hotland, his head on his folded arms as he slept deeply, both his eye sockets closed.
Papyrus, his younger brother was out patrolling at Snowdin for any stray humans to capture.

Sans was supposed to do this too, but as he said so many times, he doesn't want to capture anybody. Not like Papyrus, who was an absolute 'human-hunting fanatic'.

That is, until a faint but distinct sound resonated through the atmosphere.

It sounded like a baby crying.

Sans woke up and blearily looked around, a quiet yawn escaping him. His half-open eye sockets caught no sight of anything out of the ordinary.

The crying continued, concerning the skeleton.
He got up and left the post, looking around Hotland for the source of the sound.

After walking for what seemed like hours, he arrived outside Alphys' laboratory, the crying close by. The skeleton looked behind it and saw something strange.

A centaur foal was hiding around the back of the lab, crying its (E/C) eyes out. It's (S/C) skin had grime and dirt on it, the horse half of the body lay on the ground, the human half leaning against the wall.
By the looks of things, the infant was a female with (H/C) hair, wearing a tattered white t-shirt and a black hooded cape on her back, a small ocarina in her hand, a stick in the other.

Its tail matched its hair, but the hide was a brown colour speckled with white flecks.

"Oh my god..." Sans breathed in shock, running and kneeling in front of it, holding her in his lap, her crying continued while he tried to calm her down.

"Ssh, ssh, it's ok, it's alright. You're safe" he cooed softly, stroking the baby's head to comfort her.

"What are you doing out here? where's your mommy or daddy?"

The centaur infant buried her head in his clothing.

"You don't have...any parents? no wonder you're on your own" Sans sighed, his eyes showing sadness identical to the little foal's.
"Don't worry, you're not alone any more" he added, standing up and gathering her up in his arms, teleporting back to snowdin.