I’m starting a new D&D5 campaign. One of my players loves foxes, so I would like to provide them as an option for wild shape and animal companions, along with a giant variant.
Unfortunately, the game doesn’t have an official monster entry for foxes, and none of the similar animals (badger, cat, hyena, jackal, mastiff) are quite similar enough to just file off the name and keep the stats. They aren’t great burrowers like badgers or climbers like cats, and they aren’t pack hunters like dogs. Jackals are the closest match; red foxes are about the same size, and they have the same keen hearing, smell, and intelligence. However, foxes are much lighter than other canids, and they rely on stealth and ambush rather than pack hunting. Notably, they can leap from hiding high into the air and far away, taking prey by surprise up to 15 feet away.
Therefore, I’ll need to make a custom fox write-up. However, D&D5 is new enough that I don’t have a good feel yet for writing my own monsters, plus creating a monster for druids and rangers is a different from creating new monsters that you fight, as they spend a lot more time in the spotlight, so I want to do it right.
How should I approach this problem of creating new critters for my players? Is there already a fox writeup out there I can use? If not, what should I watch out for when doing it myself?
Preliminary research indicates that no one has statted up a fox for 5e yet. In lieu of actual monster creation rules which should be present in the DMG, here's the best I can offer, a reasonable conversion from the cat and panther.
Without doing a ton of research into foxes, and simply thinking about the iconic images of foxes, we think about them being nimble and dexterous like a cat, but more clever.
I think I would take the cat's stat block, give it slightly more int (maybe just a 4), a d6 for a hit die, perhaps another +2 to wisdom, and then switch it's power to give it advantage in a different situation (perhaps to blend into nature or hide in a burrow).
With the basic fox, I'd be hesitant to do anything that would pull it out of CR0 territory because I think a fox probably fits best there.
As for the giant fox. The big change for giant creatures is the increase in strength. I would make sure that this was the increase I made on the giant fox as well. If you use the Cat's stats, use the Panther as the giant version. The wisdom increases slightly for a panther as well, which I would also keep for a fox as this improves perception.
As you point out It seems that Foxes pounce from ambush when they attack, so it seems the Panther's pounce ability would be quite fitting for a giant fox. Though again I'd look at similar "racial" features that match with the fox's hiding/cunning than than necessarily keen senses.
This monster should still be a CR 1/4 and I think the Panther's 3d8 seems about right for this.