Brass Dragon Lineage( Dragon Magic, p. 16)
You have unlocked the power of your brass dragon ancestry and can put foes to sleep with ease.
Draconic Heritage (DM) (brass) , sorcerer level 3rd,
As a lull-round action, you can spend an arcane spell slot to cause a living creature within 30 feet to fall asleep for 1 round. A successful Will save (DC 10 + the spell slot's level + your Cha modifier) negates the effect. If the creature's Hit Dice equals or exceeds three times the spell slot's level, the effect automatically fails.