These kind of fish (I call them lunatics for a passive morons who play way too many hands opposed to maniac who also play way too many hands but do so aggressively) are very common at the mini and low stake games. All you can do with them is keep track of them - take notes - and make sure you bet, bet, bet, then raise,raise,raise every chance you get agaist them. They have to learn it costs dearly to play crap and that the occational miricle card isn't worth the numerous loses when going up against you - table image! I will sometime target these guys and when I do, there is no "Call" button - only raise or fold! After a few hands - I play tight so they notice when I'm in the pot - they get the message and either play better hands or just get the hell out of the way! I still can't get over how lucky they are as often as they are - frustrating to say the least but on the positive side, if they didn't get lucky a few times, they wouldn't keep playing garbage hands and donating their money to the table!
Oh wait a minute - I re-read you post and see it was a SnG and not a ring game - lost my mind there for a minute.

It's remarkable the donkey called your pf raise - a true moron/lunatic/maniac!
You can't bet and raise these guys in a tourney and expect to protect you stack. In a tourney, take notes on these guys and pick your spots to close them out - if you have the nuts, rope-a-dope (slowplay them to the river before lowering the hammer) is preferable to pushing them - let them hang themselfs.
