I know this is going to sound inappropriate, but there I was farming Jade Oni when a friend requested help with Counterweight West. Upon porting I noticed the wizard standing next to me had the biggest Krok I had ever seen. It was twice as big as the wizard. I thought it was a special Krok at first because I had never seen anything like it. How did he make his Krok grow? Did he use a potion? Did he feed it? Did he use an elixer? Looking at the actions of the Krok itself, it hardly moved like any normal Krok. It pretty much just remained stiff, like a rock. Most Kroks dance or move around or shuffle. This one was just rigid. I had another friend port to me She too saw how big a Krok the wizard standing next to me had. It was massive. Interesting thing was that the wizard had a big Krok throughout the entire dungeon. It wasn't one of those temporary glitches. I didn't really want to ask the wizard if he knew he had a big Krok because that would've sounded wierd, especially if it was a young person. I just let him know that he had a nice pet. I did text chat my friend regarding it though. She wanted a big Krok too. I told her that I had a krok and if she wanted, she could port to my place so we can play with it for a while and see what happens. We never made it there though. After completing Counterweight West, my friend and I went to farm Death Oni. We couldn't stop talking about the size of that krok. It was huge. After beating up the Oni the friend in Marleybone requested help with Big Ben. This time when I ported, the wizard with a really big Krok had a little Krok again doing the same things little Kroks are supposed to. It was then that I hypothesized that something in Counterweight West is making Kroks grow. I am not about to head off to Marleybone just yet because I am happy with the Krok I have, but I have to ask. Has anybody else come across this kind of thing?
The pets' graphics are apparently pulled from spells and monsters; just minimized to fit within a certain height requirement. Thus, if there is a small glitch in your client that does not tell it to resize the pet, it will look as big as its "original" form.
Thus, you can see Helephants the size of skyscrapers, Colossi that are just as big, giant Kroks and stuff like that. Once you move out of "visual loading" range of the wizard, however, the glitch vanishes because your client reloads the information about the pet. That's why the Krok was huge in Counterweight West, but was returned to normal size when you saw the wizard some time later.