I think, for once, people should trust in Blizzard, and trust that they don't spend significant resources on some jokes that lasts a day.
There have been people thinking they waste time on the April Fools jokes since like...the dawn of WoW lol. Before the age of 'Costing us a raid tier' it just wasn't quite this pressurized. Don't feel bad, parts of me still twinge thinking about someone potentially 'wasting time' when WoD is taking far too long.
Even if they did use their work time to make these things, there's a lot to be said about being allowed to take a break to exercise creativity and humor within their work setting as a way to vent frustration and angst to both each other and the community. Needless to say they probably need real mind breaks from the hard work they are likely doing. No major studio lets employees lay around on facebook all day, so regardless of our perceived time of 'not fast enough' they are probably working 60+ hour weeks. It's not really fair for us to judge that. Even having the limited knowledge we do, it's not a full picture.
But yeah, being someone who knows how to work with meshes in 3D modeling software I can say those models took them like...no time to screw them up. They probably stayed late having a drink laughing at how derpy they can make their models by moving some sliders and playing with values. Kinda like taking some of the art tools in photoshop and wiggling it all around inside an image. It's that level of simplicity.
BAD WOLF
I'm actually really sad that the "Betrayal" quest isn't actually a thing
"Chakra, when the walls fell"
It's almost like they know that I've been on a TNG binge lately
If you are particularly bold, you could use a Shiny Ditto. Do keep in mind though, this will infuriate your opponents due to Ditto's beauty. Please do not use Shiny Ditto. You have been warned.