Apart from the 10K PPC Baubleworm, there are three others coming in 9.1. You can buy these only with grey items you can farm.
Some of these are a bit annoying to find, so if you want to do your farming in advance, Maizou did a great post on the US forums explaining how to get them. Some of the sources are available only on characters up to level 30 - see the Edit at the end.
I picked up the first two without any problem, but after killing 100 Slimes at Slabchisel’s Survey on a 13, gave up and sent a 60 into Wailing Caverns and successfully picked up the Large Slimy Bone from one of the Ectoplasms. It took a couple of dozen Pickpockets for me to get A Frayed Not from the Cutpurses in Ellwyn on a level 51 Rogue outside Chromie Time, but I did get it.
I shamelessly steal Maizou’s post below.
"For anyone curious, where I farmed the 9 items:
Fresh Level 10 Allied Race (Locked behind Chromie Time, so you can’t get these on a 50-60)
EDIT: #3 and #4 are not dropping for everyone in Chromie Time. Only confirmed drops have been on fresh characters as of 9.0.5. So either create a fresh Allied Race, or farm them from their alternate locations.
- Rabbit’s Foot - Wolves in the Human Starting Area or in Mulgore, just make a new human or tauren character for quick access.
- Rotting Bear Carcass - Mangeclaw in Dun Morogh, right before the tunnel to Loch Modan (50% drop rate as opposed to 5% on the bears in Loch Modan). Can also be farmed in Old Hillsbrad Foothills Dungeon from the Bears.
- Large Slimy Bone - the two types of slimes right outside the gate leading to Loch Modan from Wetlands. Can also be farmed in Wailing Caverns from the Slimes on any level character.
- Ground Gear - Harvest Collectors at Farshire in Borean Tundra. Can also be farmed in Ulduar from Flame Leviathan and Mimiron on any level character. NOT 100% drop even from the raid boss.
Ones obtained on a 60:
- A Frayed Knot - Pick Pocketed Rogues outside of Stormwind. Bandits and Cutpurses. Only took me a few tries.
- Very Unlucky Rock - Obtained via the treasure in Nazmir that has a 100% drop on it.
And the ones I consider sadistic:
- Dark Iron Baby Booties - Only one source, from the Relic Coffers in BRD, 5% drop chance.
- Robble’s Wobbly Staff - Firelands Trash, 1% drop from any of it. (Pretty much any cata raid works, but Firelands lets you kill a lot before you can exit and reset)
- The Stoppable Force - Sunwell Trash, 1% drop from any of it. (Again, any BC raid, but there’s a lot of trash in Sunwell before you can reset without killing any bosses)"
Edit: There is something weird about what drops in Chromie Time. A level 10 will see different drops in, say, the Wetlands slimes depending what timeline they are in, and I have just confirmed an old but not levelled level 13 that got no drops on Ground Gear in Borean vs a newly made level 10 that got it in his first 4 kills.
Why the loot table of slimes in Wetlands, that are below the level of any expansion, should differ depending which timeline a character is in, and then differ even between two characters in the same timeline … Wow. That is SERIOUSLY messed up.
If you are getting the first four in the world, it is probably safest to create a new level 10 Allied Race character.
Also see Quintessence’s Blog entry
Well, I got them all, over two sessions.
I got Robble’s Wobbly Staff in one pull of the trash in Firelands, The Stoppable Force on a second run of Karazhan, and Dark Iron Baby Booties in one run of BRD.
The differing loot tables thing was seriously weird, but apart from that I have no complaints. It was pleasant to have something to farm for again.