I was just in a turn based game when at 12 moves in, my opponents' knights completely VANISHED. After double checking the move list, we agreed to a draw. Has this happened to anyone else?

why did you agree to draw? after 12 moves and your opponent loses 2 knights... hahaha...

EDIT: LOL i just watched the game... funny...

I don't see any knights vanishing in that game except by blunders...

By the way a phantom knight would be a knight that appears to be there but actually isn't, quite the opposite of your case

Strange to call a draw against a guy who throws his pieces away.

They completely vanished after you captured them.

 

PS.  After examining the move list I would have taken the draw too. 

Guys,

When I wrote Vanished, I mean completely disappeared. I never captured those Knights - they were just gone at move 12. Immediately, the game was wrecked - had to draw.

Dont be ridiculous.  The game is there for all to see.  You captured both the Knights!!  Kxf2 was the first one.  Nxb4 was the second.  You can't not know you captured them.

Stay off the waccy baccy man!!!!