Dragon claw

You transform your hand into a dragon claw to make a single melee natural weapon attack. You are proficient in the use of this natural weapon, and may use your Dexterity modifier or Strength modifier on the attack roll. The attack deals slashing damage equal to 1d8+dex or str modifier (whichever used on the attack roll), plus your spell casting ability modifier in elemental damage of the same type of the dragon scale or draconic bloodline.  After the attack, your hand returns to normal.

This spell's damage increases by 1d8 when you reach 5th level (2d8), 11th level (3d8), and 17th level (4d8).