Yes, it is done in Photoshop. I have lots of these. I have done them over several years promoting different conventions or just for fun. I have some that have taken as little as fifteen minutes, (Close Encounters of the Furred Kind) to the first one I ever did, Animal House, that took a couple of days. You have to remember that I was still pretty green when I did the first one. The one above was fairly simple. It took maybe an hour or less. I've been doing Photoshop for about fifteen years, so that helps. lol.
Here's a crossover mish mash of Aliens, Star Wars, and Spaceballs. It's Furballs!
Okay! Disney-palooza! Avoiding the obvious ones like Bambi and Dumbo that are all animals anyway...
For the sharks: Finderella
20,000 Leagues Under the Seal
Mary Pawpins (which is pretty much how Dick Van Dyke pronounced it)
Furbie Goes Bananas
The Wizard of Fuzz
Dragon Layer (err... someone might have actually done this, do NOT google!)
Pron (Also do not google!!!)
The Little Fur Maid
James and the Giant Bitch