Top two pair vs river aggression

Villain is 35/4 over 70 hands, 5.75 AF.
There's a note: "Catches nut straight and shoves 15x on river".


OnGame - €0.05 NL (6 max) - Holdem - 5 players
Hand converted by PokerTracker 3

UTG: €5.30
CO: €5.98
Hero (BTN): €4.84
SB: €11.55
BB: €5.25

SB posts SB €0.02, BB posts BB €0.05

Pre Flop: (€0.07) Hero has K 9

fold, CO calls €0.05, Hero raises to €0.20, fold, fold, CO calls €0.15

Flop: (€0.47, 2 players) K 9 3
CO bets €0.30, Hero raises to €0.80, CO calls €0.50

Turn: (€2.07, 2 players) 4
CO bets €0.30, Hero raises to €1.10, CO calls €0.80

River: (€4.27, 2 players) 3
CO bets €3.88 and is all-in

Hero?


Villain stats and that note tell me he's pretty clueless. He also bets the same amount on flop and turn, wich doesn't make a lot of sense.
The note is a single episode, so I don't know if he's one of those villains who always shove when they hit something big.

I tend to put him on a lot of Kx and I'm pretty sure he'd have re-pushed flop with K3.
KK should be in his minuscule pfr range.
Not sure about his line with 99 and 33.

Again, can any good player find a valid reason to fold here?

I also think the turn raise should be bigger.