This monster was made, when Sans and Chara were fused. Chara had a plan to reset, According to Sans' discovery, that if a human would reset on a monster, they would fuse, somehow. And, Chara succeeded. Now under Chara's control, Sans is like a Host, and Chara is the parasite, they are unstoppable, or so they thought.
What!Sans has the original powers that Sans haves but, they are 50% more powerful than before, they now have Red bones instead of white, the Gaster Blasters have now been reformed into a hideous monster. They'd still have their knife, which is their most primary weapon. They can slash the air, making red strikes, which are like bones, but red slashes instead. They also have a more... Unique form, which is their True form, named WHAT!Sans.
It's the original look of Sans instead, he has a green, with a yellow horizontal stripe in the middle, like the Chara look. He has two red vertical lines for the eyes. Brown shorts, and brown slippers. He also haves, grey 'tears' coming out of his eyes.
- What!Pap: a pile of dust What!Sans killed, he is a pile of dust that can reform into a more "Chara-like" Papyrus, he has more HP than the classic Papyrus.
- Tahw!Sans: What!Sans' Sworn enemy, he is the opposite of What!Sans, and instead of Chara taking control, it's Frisk.