The walker hanging on the right when the Reapers bring Daryl into Meridian was Maggie's friend Agatha.
The Reaper that Dog (aka Seven) attacks is one of his trainers.
Norman Reedus' stunt double wore a clear plastic mold of Norman's face under the burlap sack for the scene where Daryl is waterboarded. The water flowed off the sides of the plastic mold and prevented it from going down his throat or into his nose.
Pope and Leah have matching tattoos. The tattoo on Pope's left forearm matches the one that Leah has on her right shoulder, which was originally featured in the episode when she and Daryl first meet.