Now here's a forum question I'm pretty sure is kosher with Animation Source.
What type of NIMH critter might you be, or choose to be, and why?
For me the answer is simple, and that I'd be a Norway rat much like Nicodemus, Justin and Jenner, captured by NIMH, and to follow along the rest of Nicodemus' quote, "Put in cages and submitted to various test to satisfy some curiosity..." In my own head-canon I'd come from a different batch than Nic, Justin or Jenner, yet be subjected to similar experiments from NIMH, and I've even mentioned this on other art sites I frequent, even if I have not yet written a fan fiction regarding these facts...
As to why I've chosen to be a NIMH rat? Well that question isn't as simple.. I suppose I could see myself as a NIMH mouse, similar to Ages and Jonathan, but my scampy personality seems better matched by a rat than a mouse, so a NIMH rat is what I'll be. And another factor for my choosing a rat over mouse would be the fact that I rather dislike the way many stories portray rats as being filthy, scheming, obnoxious and generally untrustworthy vermin... save perhaps for O'brien and Bluth's spin on the rat archetype with NIMH, hence I'd rather be a rat and try to show that we're not all that bad!
And finally why a NIMH rat and not a mouse? Well being a fan of another animated story regarding a bunch of heroic rodents (Rescue Rangers) Miss Gadget Hackwrench has the brainy inventor / aviatrix mouse schtick covered, and I can't compete with that, so instead I'll just be a space age NIMH rat with mastery of Space/Time that'd rival the good Doctor.

So yeah, what sort of NIMH critter would you be, and why?