As their deadline to pick a role approaches, a call to action makes Stanley and Byron contemplate how they can be of service to their fellow horses. Starring: Jon Barinholtz, Rob Belushi, Carlos Alazraqui, Naomi Ekperigin, Katie Rich, Nicole Sullivan, Patton Oswalt, Eric Ledgin, Jamison Bess Belushi, Tara Strong, Franchesca Ramsey