The creatures you summon have evolved to have even greater abilities.
Benefit: 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.
Pathfinder Roleplaying Game: Advanced Class Guide © 2014, Paizo Inc.; Authors: Dennis Baker, Ross Byers, Jesse Benner, Savannah Broadway, Jason Bulmahn, Jim Groves, Tim Hitchcock, Tracy Hurley, Jonathan H. Keith, Will McCardell, Dale C. McCoy, Jr., Tom Phillips, Stephen Radney-MacFarland, Thomas M. Reid, Sean K Reynolds, Tork Shaw, Owen K.C. Stephens, and Russ Taylor.