Evolved Summoned Monster

Each time you cast a summon monster spell, you can select a 1-point evolution other than pounce or reach from those available to a summoner's eidolon. Your summoned creature gains this evolution. The summoned creature must conform to any limitations of the evolution. [For instance, only a creature with a reach of 10 feet or more can have the pull evolution.] Evolutions that grant additional attacks or enhance existing attacks can be applied only to Medium or larger summoned creatures. If you summon more than one creature with a single spell, only one creature gains this evolution. Special: You can take this feat multiple times. Each time you do, select an additional 1-point evolution for one of your summoned creatures. If you summon more than one creature, you can choose to apply all the evolutions to a single summoned creature, or split them between the creatures summoned.

Prerequisites

Augmented Summoning, Spell Focus (conjuration), ability to cast summon monster I