Dagger

From DwarfFortressWiki

Wielded by Kobold and Goblin thieves and master thieves only. Does small slashing damage, but has a critical bonus.

No other race has them or can even start with one. If they somehow find one of these weapons, they could train with them. Those who use daggers, slash with them, there is no stabbing or anything with them. They are basically small swords, as they can sever limbs as well.

These weapons use the Knife user skill.