Ulvenwald Hydra's power and toughness are each equal to the number of lands you control.
When Ulvenwald Hydra enters the battlefield, you may search your library for a land card, put it onto the battlefield tapped, then shuffle your library.
Near Mint - $0.50
Lightly Played - $0.40
Played - $0.30
Heavily Played - $0.30
Damaged - $0.30
Near Mint Non-English - $0.50
Lightly Played Non-English - $0.40
Played Non-English - $0.30
Heavily Played Non-English - $0.30
Damaged Non-English - $0.30