What's under the cover?

I cannot explain how excited we are for THE acquisition of this summer. Yes, buying the house was great but, in my opinion this eclipses the house and, hopefully, will be in our possession just as long if not longer. Any guesses as to what's under the cover?

A few hints:
It's big.
It's green.
It's in the shape of an egg.

Thanks Mom and Dad.

Sent from my Blackberry