"Time to feed the crows"
– Stitches before his Genocide Battle
A mysterious, mangled and discomforting monster, Stitches is a ghost possessing a scarecrow. He was at one time a human boy named Patrick. He and his family hid monsters near the end of the war, leading to them being killed by human soldiers when they burnt down the farm they lived in, with them in it. Patrick came back as a ghost, managing to posses the mangled remains of one his families old scarecrows.
He was thrown into the underground with the rest of the monsters and now resides in his "Freaky" Farm, surrounded by his scarecrow "Family".
Stitches looks like a scarecrow missing one eye. Also, his arms are twisted, so that when at rest they appear to be in the same position as a strait jacket. His mouth is halfway stitched shut.
Stitches is seemingly completely insane, often to talking to people who aren't there. He originally mistakes the Protagonist for someone named Clarice, perhaps further proof of his insanity. He will go from crazy but harmless to violent and murderous if you a) kill one of his crows, or b) Destroy one of his dummies. During his pacifist route he will try to keep you from leaving the farm, until he figures out you're not Clarice and you drag his mind back to reality.
Shadow Crows: Crows will fly through the battle field, dealing damage if they hit your soul.
Pitchfork: This works basically the same way as Asgore's tridents, but less powerful