This article is from the NARF--The Nifty Animaniacs Reference File FAQ, by Lee Cremeans firstname.lastname@example.org with numerous contributions by others.
The Warners are not to be confused with the Two Tones. Here's a few
reasons if you still have any doubts:
live in the Warner Bros. water tower
are not a recognizable species
have distinct ears and non-bushy tails
wear coloured clothing
are not black and white (Warners have red noses!)
are out of control
The Two Tones (Foxy & Roxy):
Live in Two Tone Town, a suburb of Acme Acres
have fox-like ears
were "drawn in shades of gray"
are generally predictable
are usually quiet
The Warners do not fall into any general species category. They are not
dogs, cats, llamas, puppy-children, or even skunks. A complicated
explanation is that they are styled after the 1930's characters which
were not meant to be any species at all, only a humanized `inkblot' of
sorts. If you want the simple explanation, they're Warners (or just
plain cute). One thing's for sure: the Warners are very good at
irritating people in the show.
Animaniacs, unlike the Tiny Toon Adventures episode of a similar name,
does NOT end with an exclamation point (!). Animaniacs is in no obvious
way related to "Animaniacs!".
Also, while "Two-Tone Town" may have hinted at A!'s existence, it's not
officially a pilot to the show in any conceivable way.