Magic Fang, Greater(Player's Handbook v.3.5, p. 250)
Level: Druid 3, Ranger 3, Death Master 3, Urban Druid 3, Dragon 3, Scalykind 3,
Range: Close (25 ft. + 5 ft./2 levels)
Target: One living creature
Duration: 1 hour/level
This spell functions like magic fang, except that the enhancement bonus on attack and damage rolls is +1 per four caster levels (maximum +5).
Alternatively, you may imbue all of the creature's natural weapons with a +1 enhancement bonus (regardless of your caster level).
Greater magic fang can be made permanent with a permanency spell.