click on the dinosaur to start and then just let it move around once it has stopped you can click on the eat button to make the pet dinosaur eat another tiny/small dinosaur or click the on the bell to make the dinosaur play the bell. You need to make sure your pet isn't too thirsty else the game will end.You reduce the thirst by click on the lake which makes the dinosaur drink from it.
I used the new tutorial in the help baer to make this everything is from the relevant scratch libraries apart from the water hole which is from google images. If you like the bell I have a whole project that lets you make music here is a link to it: http://scratch.mit.edu/projects/31828172/