i do say cat, not a cougar but possibly a wildcat or domestic. I say this for a number of reasons,
1.gray foxes have a larger neck and a prominent snout. i zoomed in on picture two and saw a small neck and no prominent snout.this leads me too observation number 2.
2. Grey foxes have smaller hind legs then felines, as they (felines) get much of their pouncing, climbing and running power from their hind quarters, so they naturally need more muscle in that region of their body. you can see this in pictures 1-3.
now the last two pictures (#4 and #5) look like two completely different animals. Number 4 looks like a canine, possibly a coyote or fox of some type, that looks like it's had it's fun and is now leaving. Though number 5 is in fact a member of the feline family. This is quite obvious if you have seen a cat(any member of their family) stalking or just in general, running, or standing. I know that animal in #4(probably a canine) could not of in fact turned around, ran down the slope a bit, and gotten in a stalking pose in the matter of two short seconds.
So my theory is that 1-4 is probably in fact a fox, while five is a feline. This could of happened by the fox already up and lazily walking away, while all of a sudden a feline (looks to be a cougar, but unsure of size) shoots through the brush at the top of the bank possibly hearing something down below ( doesn't look too fed), and not being able to smell anything (either wind going away from the feline or bank stops it), rushes through the foliage, only to scare off the prey ( whom it could of figured was a coyote, but by being so young, is willing to risk it for a large meal ~ has happened). You can see a disturbance at the top of the slope, on the left hand side, if you look at frames 4 and 5.
haha this is probably my longest post but hope it helps in some ways, oh and BTW I have seen all of the animals I've mentioned, alive and wild.