Saguaro Cactus: Tropical Grassland: Giraffes: Lions: Lizards: Arctic Conditions: Penguins: Polar Bears: Dolphins: Frogs: Snakes: Small-eared zorro: Other Creatures. Saguaro Cactus. 1. Its expanding trunk allows it to take in and store a great deal of water when water is available. 2. It does not need a lot of water to survive. 3. The flower only opens on cooler nights and is closed during.