this lesson from Robert Kaplinsky's website and it was GREAT!
The lesson comes with some videos to show and questions to ask. It is a great introduction into transformations. My 8th graders loved the link to gaming and it is also going to tie in nicely to my upcoming Hour of Code (next week).
One modification I made to the lesson was to give each student a notecard where they could draw Ms. Pac-Man on one side and the reflection on the other. That way, if they had to "flip" over the notecard to follow along with the video, they know she reflected rather than rotated.
This was a great lesson and I'm glad I found it!