Once your 120 there are also a few rares and treasure chests that drop Pet charms (I've found some from the Jani Chests/quests in Zandalar). There's also a good list to start with from the wowhead comments (Under Polished Pet Charm) 55 Pet charms give or take listed sans any world quests or War camp...

The Strategies on Xu-Fu also work pretty well (Primarily relies on pets with the ability to damage when attacked) which ignores the shell.

Guessing it goes something like this: 2:55PM - "This is stupid. Blizzard really needs to up the spawn rate. I'm not sure if I'll have time this season to get the yeti." 3:07PM - "Glad I got my yeti. The spawn rate seems fine; people just need to put a little work in." On a more serious note, this w...