Let me go on record as saying I think "Dire" things are stupid. I suspect the idea comes from the Dire Wolf, a prehistoric canine and the largest on record. Fine. Giant wolf. Here's the thing there: Worgs are cooler, and once you've introduced Worgs, Dire Wolves are just confusing.
Dire Bears... okay, a giant bear. Why can't we call them giant bears again? Does that not sound metal enough? You know "bear" and "wolf" are actually the results of "taboo deformation" - that is, in several languages they were called one thing, but people so feared them they stopped using their "real name" for fear just saying it would attract their attention. Thus they called them things like "the brown one," until eventually that taboo reference replaced the actual name.
And how about Dire Rats, Weasles and the like? Here's what I think about that.
(removes your glasses, snaps them in half, and slaps you)
But... there is one creature of the natural world I think is grossly under-represented in D&D. A creature so awesome it rhymes with said adjective.
I speak, of course, of the Virginia Opossum.* But how to make an Opossum dire? By the template in 3e, we make it bigger and stronger. But to me, the main thing about Opossumsis that they are smart, and they climb.
Hit Dice: 3D8+12 [opossums are hearty]
Attacks: Bite +4 melee
Speed: 20ft (opossums kinda waddle around)
AC: 13 (+1 natural, +1 dex)
Abilities: STR 14, DEX 12, CON 19, INT 5, WIS 13, CHA 5
Skills: Hide +8, Listen +3, Move Silently +8, Spot +5, Climb +8, Escape Artist +8, Disable Device +5
Feats: Stealthy, Improved Critical (opossums always go for the throat)
Decide the rest for yourself. So, after ranting about Dire animals, why did I stat one up?
Because the goblins need something to ride.
*The "O" is silent. Why? Because the Opossum mother-fucking told you so.
Art Credits: Scary Bear Sexual Humiliation Scene by Theodor Severin Kittelsen whose art you should look up. Opossum by me.