Can you use a creature as an improvised weapon?

[Quoz]

Title states it all, really. Particularly with Tavern Brawler feat.

Assuming you would have to succeed at a grapple first, unless for some reason the creature is willing.

The only RAW way to gain proficiency that I know is Tavern Brawler. Kensai weapon choice may also work, although I doubt it is RAI. (I'm assuming a medium creature will probably be a heavy weapon)

Improvised weapons have default damage of 1d4 and a thrown range of 20/60. Could theoretically throw straight up for 6d6 fall damage and prone. Takes an attack to grab and another to throw, so damage is kind of underwhelming but it would bypass AC.

Not sure how damage to your "weapon" would work. Probably 1d4+mod, the same as the damage it deals. To offset, this would probably impose disadvantage for having them actively oppose you.

You could also argue for gaining cover, depending on the size of the creature.

So what do you think? Would you allow this at your table? What restrictions or limitations would you add? How would you abuse it if allowed?

[tieren]

Goliath barbarian dual wielding halflings?

[JackPhoenix]

Yes, I would allow it.

First obvious limitation is that you're limited by your encumberance. You're not swinging 250 lb armored orcs around with Str 10 (and propably not even Str 20, if you have heavy gear of your own). Second is the creature's size compared to yours, especially when throwing is concerned. While human throwing cats (https://i.imgur.com/zwmuVWU.gif) around may be possible, you aren't getting 60' range on throwing another human, especially straight up. I'd say two size categories smaller for that 20/60 range (it also fits that humans are two size categories smaller than true giants... ogres and trolls would have some problems), with lower range for creatures one size smaller (5/15, propably) and impossible to throw same-size creatures or larger (that's what shove and Open Hand monks are for). (on that note, 6d6 AC and weapon resistance/immunity ignoring damage and prone status for 2 attacks is definitely not underwhelming... grapple and shove is one of the better tactics, and that's with no damage added). Creatures grant cover as normal, grapple or not.

Agreed on damage recieved by both the "weapon" and the target, and disadvantage. Overall, good for rule of cool, but not viable as a standard tactic.

[rooneg]

"An improvised weapon includes any object you can wield in one or two hands, such as broken glass, a table leg, a frying pan, a wagon wheel, or a dead goblin."

So assuming the creature is small enough to hold in one or two hands, and isn't fighting back very much (i.e. dead, grappled, or paralyzed in my opinion) sure you can use it as an improvised weapon.