Starting as a Small Zombie, I Cultivate to Immortality by Growing Plants

I've transmigrated, and my cheat is Plants vs. Zombies—and I'm the zombie… "Sunflowers produce one sun a day, which contains the full spiritual energy of the Qi Refining stage? If I fill all 45 grids, wouldn’t that mean…” “A pea from a Peashooter is equivalent to a full-power strike from someone in the Qi Refining stage?” “Whoa, is this a Squash? It just flattened a mighty cultivator at the Foundation Establishment stage with one smash!” “This Nascent Soul elder, I offer you a spiritual plant called the Doomsday Shroom…” “Huh? These two plants… can hybridize?” “Zombie Almanac? Open.” “A zombie body can be upgraded, and I can even replace it with different zombie forms as my base… Quick, bring me that perfected Sacred Body covered in green moss!” Original Webtoon