After beating level 1-4 in Adventure Mode, Crazy Dave will give you a greeting and first, he'll dig up your three Peashooters and will give you a Wall-nut to play Wall-nut Bowling. At nighttime, he says that you can't receive falling sun from the sky, so you must use Sunflowers/Sun-shrooms to beat them. Later, Dave will greet you at your backyard and he says that mushrooms are nocturnal now, as they sleep during the daytime. After beating level 3-4, Crazy Dave says that the plants can't stay out in the sun too long, so you must cheer up your Peashooters by blowing in the mic. Later at nighttime at the pool, Crazy Dave will say that some people used to call him "Fog Man" and later, he'll give you a diamond for finding his Magic Taco, then he'll tell you that he and his brother, Harvey are bored and they break vases. He'll start telling you to play Vasebreaker. During the blackout, there's no light and thunder will strike so you can see your lawn. At the roof, there's no soil and you must use catapult plants and later, he'll teach you how to do Zen Garden. Later, Dave will warn you that he hates Bungee Zombies and you must stop the attack. Before the final battle, Dave will say that you must defeat the leader of the zombies.
This isn't known if Crazy Dave can have multiple items in a single trunk.
You can see a figure of Lex in his car.
Crazy Dave is grabbed by the Bungee Zombie during the final battle and you can see his shoes.
On the top screen, Crazy Dave will tell you when you're in the Mini-games, Puzzle and Survival selection.
Crazy Dave likes bacon if you purchase it in the DSiware version.
Besides you in the game, Crazy Dave is the only known living human being.