Serpent's Venom

Ability to wild shape,

You can spend a usage of wild shape to gain a secondary bite attack (at your base attack bonus -5 and adding 1/2 your Strength bonus) that deals bludgeoning, piercing and slashing damage equal to a dagger appropriate to your size (1d4 for Medium, or 1d3 for Small). In addition, the bite delivers a toxic venom (Fortitude save DC 10+ 1/2 your HD + your Con modifier; 1d6 Con/1d6 Con).

If you already have a bite attack, it just gains the toxic venom part of this feat.

You can spend a usage of wild shape to gain a secondary bite attack (at your base attack bonus -5 and adding 1/2 your Strength bonus) that deals bludgeoning, piercing and slashing damage equal to a dagger appropriate to your size (1d4 for Medium, or 1d3 for Small). In addition, the bite delivers a toxic venom (Fortitude save DC 10+ 1/2 your HD + your Con modifier; 1d6 Con/1d6 Con).

If you already have a bite attack, it just gains the toxic venom part of this feat.

You can deliver a toxic bite attack reminiscent of the viper.