Three characters got uploaded enmass recently (And unfortunately the tumblr they originated from is dead, so no proper source, unfortunately), but they're pretty closely related to the same base character.
There's Spines, or Barb, a female version of spike_(mlp), who should be tagged as such due to simply being a crossgender version, but the other two are a bit more complicated.
There's ava_(inuyuru), who is basically the somehow less-controlled (Wouldn't think that was possible!) version of Inuyuru's Spines. Should that just be tagged as spike_(mlp) as well?
Finally, there's Shiawase, who has the same appearance, except for the eyes being wider and the "hair" being longer. She's a lot more innocent than the other two, although Inuyuru being a porn artist, she's seen her share as well. She almost looks like if Fluttershy became Spike, and I feel she should be considered different, but is that how we do things?