Q: "Is there a conscious effort to avoid adhering too closely to 'real world' animal classifications, in the same way that real world references are avoided in flavor text? The February 9th question brought up Giant Solifuge, but as a whole there are quite a few generalizations in terms of creature types. I understand that it isn't necessarily in the best interests of the game to create a lot of 'one of' creature types (like Octopus), but is there an attempt to generalize things as 'Magic Insects'? Some others I can think of are Horseshoe Crab, which is actually a chelicerate (as are arachnids). Bane of the Living, Clickslither, Ferropede, Gigapede, Lithophage, and Mortipede all seem to be closer to myriapods (centipedes and millipedes). Plague Fiend seems rather solphugid-like, and Gleancrawler seems more like a crustacean. Also, is the decision of creature type made before the artwork is commissioned, or based to some degree on abilities and the art?"
A: From Brady Dommermuth, Magic Creative Director:
"Big question, Ryan. Creature types are tricky; they’re the one creative element on a card for which there’s a direct mechanical function. In all other parts of the card, the mechanical aspects and the creative aspects operate more or less independently; not so with creature types.
"To me your question is really about where to draw the line on a particular creature type. For example, maybe Hound and Wolf could be unified under a Dog type. Or maybe all Hounds, Wolves, Hyenas, Jackals, Dingos, and Foxes could be unified under a Canine type. Then, if you’ve got Canine, you could have Feline, Bovine, Ursine, Equine, Ovine, and Porcine. And then you could have Primates, Cetaceans, Rodents, Ungulates . . . aw, heck, how about just a Mammal type? I’m joking, of course, but the point is that we don’t want too much taxonomical complexity or too many scientific terms in Magic. Whether or not a particular made-up creature such as a Gargadon gets lumped in with Beasts or gets something more specialized depends on many factors, not the least of which is its overall coolness.
"As for the second part of your question, artwork often influences the decision about a creature’s type, mechanics less often. But when mechanics do have influence, they exert a strong influence. Some examples are Spider, Shade, Specter, Sliver, and Slith (hey, why do they all begin with “S”?)."