The moment when Zipper get infected

Some dogs just know when something is up with Werewolves!

Not including this in a dog lineup because it's a werewolf film, but because of Zipper the dog (played by the talented dog actor Solar) who gets infected with the werewolf blood and "werewolfs out" on everyone in the 3rd act.  Also because of the above "neighborhood mutt" moment, when Jimmy (Jesse Eisenberg) starts acting a bit strange one night in his bedroom.