Science Cartoons

Somebody sent me this a while back, now I forget who. Sorry!
(Hat tip necta)
Knock knock. Who's there? T-Rex. T-Rex who? T-Rex has just eaten everything on the Ark, and you're next punk. (Caution, a little profanity. You can take it, right? :D )
Or a popup, if you can't read it. View image