Isn't Umbridge despicably morbid? There were a few times when Sinick's dialogue for her made me cringe.
*grin* Snape is the kind of survivor that would hold onto any available chance. I love that about him. He'd never give up - and not in a showy gryffindor display of stubborness, optimism, and heroics - but in his own quiet 'this is what has to be done' sort of way. Though Harry's naive, hopeful optimism is welcome nonetheless to brighten up the day. Even if it's a completely crazy lizard conquest, I suppose it counts for something. :) He wouldn't be Harry without it.