Google hides an Easter egg in every new release of Android. This Easter egg is usually related to the name of that Android release and sometimes also contains references to the previous releases.
The updated Developer Preview build of Android 5.0 Lollipop also contains a new Easter egg that is inspired from the massively popular Flappy Birds.
The Easter egg is a complete copy of the Flappy Bird game except that the bird has been replaced by Andy and the pipes have been replaced by lollipops.
If you are already running Android 5.0 Lollipop on your Nexus 5 or 7, head over to Settings -> About Phone and tap on ‘Android Version’ a few times. Then, tap on the Lollipop that shows up on the screen followed by a long press on it for some Flappy Andy action.