So let’s see, what’s next? Ah, we have some sort of magical ox. That’s okay, I guess, they can’t all be interesting. Some Fantastic Beasts are quite plain, or cute little critters that won’t make very deadly D&D monsters. They can’t all be be party killers after all.
Does this ox have anything special going on? Oh, it’s gold and it’s blood is useful. Not really something that affects its monster stats. It’s also pretty big and strong? I could have some fun with that at least. I guess?
Lets just check the artwork for anything out of the ordinary…
…wait…how big is this thing?!
Re’em

So what at first glance looked like a rather dull Fantastic Beast turned out to be a fun little upscaling of the standard ox/auroch you find in D&D, with a bit of extra punch thrown in. Not the most unique or elaborate of conversions, but certainly one that will make for a memorable encounter.
Fighter: Remember that time you got hit by that cow?
Barbarian: Yeah that hurt a lot?
Bartender: A cow beat you up?
Barbarian: This one was the size of a house. A big, meaty, angry house.
As with a few previous Beasts, the description of this entity skirts the line between creature types. I went with ‘monstrosity’ over beast, as I’ve done before, because beasts can be summoned. They can also be the form a character polymorphs into. There are challenge rating 7 beasts in the game (T-Rex are CR 8, for example) that the heroes can transform into, so it wouldn’t be too bad. Nevertheless, allowing a player to turn into/conjure a ‘gargantuan’ beast is something you should think about very carefully.
As for allowing players to try and tame a Re’em so they can ride it… I’ll leave you to decide the animal handling roll they would need to make before you allowed that to happen.
Thank You For Reading
From Acromantula to Re’em, we’re make good progress turning all Fantastic Beasts made into Dungeons & Dragons monsters. Find them right here.