The last thing you remembered was falling into the underground, you were a tiny, trying to climb MT Ebott to prove yourself, but you fell in a giant hole

When you woke up, you were in a large glass terrarium, with dirt, sticks, and fake rocks as a makeshift shelter, there were two small bowls, one of water and the other with food

The terrarium was on a counter in a kitchen, the scent of pie lingered throughout, you had no clue of Toriel looking at you from outside the terrarium, until she spoke up

Toriel: "My, it seems you are awake, little one"