Does he look familiar ? If you use Google Chrome, this cute little retro dinosaur should do. He appears on the 'no internet' error page. But it's also a game!
This is that easter egg game extracted from the open source Chromium repository.
All the kudos goes to the Chromium developers! The only difference is that you can play this great game any time, even when you are not offline. Enjoy.
This is the later version, that also includes those pesky pterodactyls!
It's available for free on Google Play
http://nellyfish.com/trexrunner
Full source code is available here: