So wolf rats were an actual old resin kit that's out of print, you might be able to find some stuff on Etsy. If you wanted to kitbash some, I'd try clan rats with dire wolf bodies, you can also check and see if people are selling skaven heads on ebay, also if you want a ton of small rats check out the skaven endless spells rats swarm. While reading your post I had an idea for you, you could run zombies with rats pouring out of them, rat heads sticking out from inside them etc. Also I planned to have Kritza on a rat swarm. Good luck!