XL-Nut

Info

 * This is your highest line of protection.
 * It is guaranteed that one use of it may block almost every cat
 * Heavy Duty Wall-Nut that can be compared with others

Strategies

 * Plant at least one so you can have highest protection

Trivia

 * This is one of the unbasic wall-nut plants along with Heal-Nut
 * This is the strongest plant in Cats Revenge. Ironically, it isn't the most expensive plant.