Was vs a reg, but didn't have much stats on him, it feels so much like trips or slowplayed AA/KK, could be a tilt too, couldn't find any bluffs but spazz outs. He slowplayed AA vs a 4-bet vs me and I had a note on PT4 that he also called 4-bets with KK
Is it a call or fold OTR?

PokerStars - $2 NL FAST (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

Hero (BTN): 102.2 BB
SB: 180.52 BB
BB: 66.06 BB
UTG: 345.62 BB
MP: 279.96 BB
CO: 233.48 BB

SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has Q J

fold, MP raises to 2.57 BB, fold, Hero raises to 9 BB, fold, fold, MP calls 6.43 BB

Flop: (19.5 BB, 2 players) J 4 4
MP checks, Hero bets 6.14 BB, MP raises to 12.27 BB, Hero calls 6.14 BB

Turn: (44.04 BB, 2 players) 8
MP bets 14.94 BB, Hero calls 14.94 BB

River: (73.91 BB, 2 players) T
MP bets 72.54 BB, fold

MP wins 72.54 BB

I have no idea what to do OTR, that's such a weird line. What hands would we 3bet flop with? A4s,KK,QQ?

You can probably fold a lot of your jacks here. I think You're right on the call and fold fringes with QJs. Imo it's pretty ev neutral with this hand. I think you just call it off purely because the turn was so good for the backdoors in his x/r range. This is such a marginal spot though.

Definitely think about how much KJ and AJ you have here because it's important to call some of your jacks. I don't know what you're doing with your KJ, AJ, JT here, so it gets pushed toward a fold if you have all of those combos in your range on the river.

his flop and turn sizing are so small that you will probably peel flop/turn with a lot of QT, Q9, random spades, AK, any pair, plus overpairs probably raise turn a decent amount.
this is pretty high up in your range on the river - definitely top 50% - and folding it would probably be a theoretical mistake. plus his sizing and line are just so weird that I would be a lot more inclined to look him up b/c that increases the likelihood of some random spazz. so even if you flat a bunch of overpairs on the turn and this isn't THAT high up in your river range, I am still loathe to fold tp vs an unknown's weird ass line representing almost nothing for value

btw i think AA/KK are pretty unlikely and that the situations you experienced before with him slowplaying overpairs aren't good proxies for this one. flatting AA/KK to 4bets is incredibly standard in any given position. flatting a 3bet oop with them is incredibly nonstandard (&bad)

I misread the hand and thought you had QQ and I thought that was a fine fold, depending on how you construct your 3bet range. If you're a bit more merged you probably have to call it.

If you're super polar preflop this is a great spot to range bet but if you're a bit more merged then you want some check backs.

Would rather fold QQ than hands blocking Jx. Ofc we get owned by KK/AA so maybe you want to call off with AJ/KJ then instead? i haven't done combo work on this.

AK isn't too hard for him to have.

If he likes to flat AA a lot because he likes the deception value then I don't see why he would want to ever construct a bluffing range for balance purposes. Exploitatively it doesn't seem thrilling to try to get top pair to fold at 1 spr. There's not enough natural bluff candidates ott. I don't think a 200z reg will just spazz out repping nothing almost ever in this spot. Only way he takes this line with a bluff imo is if he thinks people/you are nits otr and that's possible but I don't think that's something to worry about, and if it is then go ahead use that move yourself. I'd fold. Maybe Mythril is correct though and he rarely flats with AA.

There's no reason to expect villain is unbalanced imo, his line is perfectly fine. River we can't call with all pairs.