Glad to see I'm not the only one that into her characters that she does this.
The day the Shattering patch was released, I started an Undead Huntress. I figured that was as close as I'd get to being a Dark Ranger in service to the Dark Queen... so, I was stoked. Aside from getting to experience the revamped visuals and quest lines (AWESOME, by the way... if you have any passing interest in the Forsaken storyline at all, MAKE AN ALT and do the quests... you won't regret it!), I figured I'd justify the pet part of my hunter/fake-ranger by only taming things that would be undead appropriate. Here's what I've got so far.
Started with a Plagued Bruin from Tirisfal Glades as soon as I could. Technically, the spider I had could fit, but spiders imho are a little (technically) weak for solo play. Still, I might get a bone spider for the coolness factor... it's certainly undead appropriate.
When I got to the quest for the Diseased Hawks, I got one of those ASAP. Isis is my nearly constant companion, now.
Got to EPL, and saw the green runed demon dogs. Malfoy is awesome and I usually use him in groups due to his higher dps.
Pretty soon, I got one of those lovely red Carrion Beetles for my tank pet. It's basically the same as a turtle as far as abilities (including shell shield), but where a turtle doesn't fit undead, a beetle, and a carrion one at that, is perfect in my opinion.
Also picked up a Scorpid (Duneclaw Broodlord) and a Serpent (Sunburst Adder) for her recently for a little variety. Scorpids are very orcish, IMHO, but also creepy and a little scary, just like snakes... and spiders. Not quite rotting and undead, but not cute and fuzzy wuzzy either. I lump them together into the "creepy crawly" category.
I plan on getting the damaged silithid from Thousand Needles as soon as I hit 69 (and naming it Migraine)... and maybe that newly tamable black wasp once the patch hits.
I'd get an undead boar, but I don't like their special... I don't have any shots that cause bleeds, so it's kind of pointless for me. Good for a group, maybe.
But, absolutely NOTHING with fur unless it's rotting. Spirit beasts ARE cool and a saving grace for us undead, since "ghosts" are undead, too.
Cheers to everyone else going thematic with their pets. I love reading about the ideas others have for the themes!