To me... Sparkle dogs are anything that has eye-murdering colors lumped onto one character and/or can't be a convincing character to save their lives. Hallow-yenas are a good example of eye-murdering.
Unnaturally bright colors don't really make a Sparkledog or Glittercat - though it's hard to draw the line between fantasy and, as Draak put it, unicorn barf. Again, that's where the character comes into play.
If your character has a background with a reasonably developed past, somewhat formulated appearance, and a believable personality, you're Fantasy. (Or SciFi, whatever genre you prefer.)
But since formulated appearances can be lost on other people, most Sparkledogs and Glittercats have the following:
A background where they:
- murdered everyone in their pack for no reason
- their parents were murdered for no reason
- they have random demon/angel powers
- they're the last of their bloodline for no reason
- no reason for having no reason (aka the "I feel like it" scenario)
A personality (or lack of one) like:
- Angry/dangerous all the time, without probable cause
- "OMG I CULDNT LIVE WIT OUT MY MATE!!!1"
- Need to be the center of attention all the time
- Often throws their character off cliffs (or injures them in any other way) to get said attention
- Injuries Heal Immediately and they Never Die (aka "Infinite Phoenix Down" disorder)
- Don't want to follow rules set by RP they join
- Want/Need to be Alpha animal/be in control
- "*Rips your head off for stepping in my territory*"
- They flip out when you tell them you don't want them in your semi/realistic rp
My, I think I've rambled a little.