Encyclopedia

Plants' encyclopedia:
( * is an upgrade that can be bought from Crazy Dave's Twiddydinkies )

( ** is not an upgrade, but can also be bought from Crazy Dave's Twiddydinkies )

Zombies' encyclopedia:
Imps in I, Zombie are the weakest, taking exactly 3 normal hits.

* Means this zombie has a Giga form.

** Means this zombie has an Invisible form in Invisighoul.

*** Means this zombie does not have an almanac entry.

† Means this zombie has a smaller form in Big Trouble Little Zombie.

There are also Ducky Tube Zombie versions of Flag Zombie, Conehead Zombie and Buckethead Zombie zombies and the Zombotany Zombies (except the Squash Zombie).

References:
- videos Zombie-HP test by MrVuong313

- Gargantuar Imp HP test [clip]