Magic Fang, Greater(Player's Handbook v.3.5, p. 250)
Level: Druid 3, Ranger 3, Death Master 3, Urban Druid 3, Urban Ranger 3, Consecrated Harrier 3, Vadalis Beastkeeper 3, Dragon (SpC) 3, Scalykind (SpC) 3, Bestial (BoVD) 3, Scalykind (PG) 3, Scalykind (DD) 3, Dragon (Dr) 3, Serpent (OA) 3,
Components: V, S, DF,
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One living creature
Duration: 1 hour/level
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)
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.