This is Kauffman. He was a very jolly unicorn, despite having no cutie mark and was happily married to an earth pony and had a filly unicorn.They made him a scarf to show their love towards him. However, that changed when Vault-Tec demanded him to be moved to a vault without his wife or daughter. He refused to leave without his wife or daughter, but they forcefully dragged him to the vault. He knew of the fallout and went into a deep depression and psychosis. He consumed prescription medication and developed a drinking habit to deal with it, he got his cutie mark from this. Eventually they ran out of alcohol and prescriptions and he preceded to slaughter everyone in the vault from psychosis. He now travels the wasteland, killing for the sport of it. He never takes off the scarf, he wears it as a reminder of what he lost that was dear to him.