Fold against LAG donk?
 

Villain is a LAG/maniac (80/22/4.10 after 40 hands). He bets when checked to and overplays marginal hands, but I haven't seen him donking.

Cryptologic 3.00/6.00 Hold'em <font color="#0000FF">(5 handed)</font> link

Preflop: Hero is Button with Q[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/diamond.gif[/img].
<font color="#CC3333">UTG raises</font>, <font color="#666666">1 folds</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">2 folds</font>, UTG calls.

Flop: (7.50 SB) 4[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
UTG checks, <font color="#CC3333">Hero bets</font>, UTG calls.

Turn: (4.75 BB) 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG bets,

Re: Fold against LAG donk?
 

Weird spot for him to bet, but I don't see any alternative to folding. Showing down K high in small pot blows, esp. when we'd have to call another bet. If you raise, he's probably 3-betting or calling down. If we're behind, we might have 6 outs. If we're ahead and we don't improve, we still might get pushed off on the river. I like folding.

Re: Fold against LAG donk?
 

I like a call here. Our shot at drawing to the pair with the implied makes the call pretty close, plus I expect him to check to us on the river sometimes so we can get a free showdown, as I'm not sure we are beat.

Re: Fold against LAG donk?
 

that's a nutty bet. I don't think we're giving up much by folding. If anything, he made a mistake by not allowing us to further hang ourselves.

Result
 

I agree with the postrers that the turn donk move doesn't make any sense.
I folded and villain showed QJo.
I was a bit angry because my preflop 3-bet was a bit thin but it turned out to be good given I dominated him.