His name is a portmanteau of "hard hat," a type of helmet predominantly used in workplace environments such as industrial or construction sites to protect the head from injury due to falling objects, impact with other objects, debris, rain, and electric shock; and "Wall-nut." His Facebook page description mentions Sunflowers.
Plants vs. Zombies Adventures Facebook page
Hard-nut's rough exterior belies his soft, squishy insides. "I don't whistle at the Sunflowers, like some other plants," he says gruffly, scratching his belly against a nearby post. "It's disrespectful and objectifying. Also I can't whistle."
- Despite his description saying it is stronger because he has a "hard, crunchy" shell rather than the Wall-nut's "soft, chewy" one, their shells had the same health. His health was higher because of his hard hat, giving him 2 additional degrades.
- This also made him the first plant in the whole series with headwear that protected the plant.
- He could resist a smash from a Weightlifter Zombie. It would trigger the first degrade, but the next bite of any zombie will make him trigger his final degrade. This may have been a glitch. Only a Gargantuar Zombie could instantly kill him.
- When zombies ate him, they also ate the construction worker outfit with him.
- When the player won a level with a damaged Hard-nut, he would look undamaged at the end of the level. The same goes for Wall-nut and other knocked out plants.