Frisk has spent her entire life surviving by stealing from the wrong people. After a failed heist lands her in the hands of the Black Roses, the city's ruthless human crime syndicate, she is offered one impossible choice: infiltrate their greatest rivals, the Monster Syndicate, or die. Armed with nothing but a fabricated story and orders to destroy the Family from within, Frisk earns the trust of monsters she was taught to fear. But the deeper she sinks into their world, the harder it becomes to believe the lies she's been told. As loyalties blur and dangerous friendships form, Frisk finds herself caught between two criminal empires on the brink of war. When her betrayal is exposed, both sides force her to make a choice that could cost her everything. In a city ruled by blood, trust, and family, survival may no longer be enough.

NOW WITH UNDERFELL GASTER!

So... what would happen here?

(Underfell Sister Scenarios) Being the only sister out of the three siblings in Underfell is tough. You have more problems, and being the youngest, you still have plenty to learn! Join me and these fellow readers to venture what happens in Underfell with Sister Scenarios!

Spoilers! If you have not seen both pacifist and genocide routes of Undertale, get out! You have been warned! Sans finds a baby on the streets. The monsters of Undertale decide to adopt them. What can possibly go wrong? More than they thought. Undertale, images, music, and all that stuff does not belong to me. All credit to them!

"Like Underfell, but a different AU."

Read le' title!

(y/n) =your name (h/c) =hair color (f/s) =favorite shirt (h/l) = hair length

What happens when the Gaster Gang handle a human child situation? Read and find out! Based from Bun-bunmuse art story. ps. the reader is 5 year old girl ?