I based my lesson on weird animal facts, which the students really seemed to love.
This slideshow contains statements like "The sloth is the world's slowest animal" and "The ant is the world's most common animal", and they have to answer true or false. There are lots of nice pictures, and links to cool youtube videos embedded in the slideshow.
The ppt took about 35 mins, with commentary/explanation from co-teacher. The worksheet took around 10 mins.