The frog stared at the two men. And one of them stared right back.
"Wait?" Dean couldn't believe what was coming out of Sam's mouth. "What do you mean 'wait'? That thing probably ate Fred!" He was more than willing to shoot first, cut next, then if there was anything left ask questions. At the moment he really didn't care. He wasn't going to lose a friend. Things had been going so well.
The frog on the other...webbed foot...had decided that it was taking the opportunity and luck. It leapt off the wall to another and then another. Dean was shocked enough that he didn't start shooting. The frog took a risk perhaps and leapt on Sam; there was a pause, as if the frog were considering something - it was, or she was - a good lick for thanks. Instead the frog jumped away and out the open door.
"Sam!" The older Winchester was torn. Check out Sam or run after the Fred-eating frog!