Sure theres pro's and cons.........For instance.........the Stegasaurus only eats vegetables and leaves, so you wouldnt have to worry about getting bitten by the three legged donkey that only popped down the local shop for a pint of cherry milk, surely thats a pro.
And as for con's, yes, unfortunately there are some.....Like the fact that the dolphin who's name is Gerald (you know him right?)only comes out on a full moon to chew the cud. Any other day and your left in the company of Adolf the inbred water rat.......Bad times!
So I guess you need to make the decision for yourself....