Brickhead Zombie

Brickhead Zombies and their world-themed versions in Plants vs. Zombies 2 are basic Zombies with armor on their heads, greatly increasing their toughness. However, unlike Knight Zombie, Blockhead Zombie and Jurassic Fossilhead, these are Veteran Zombies, which are upgraded zombies that only appear in levels of world expansions. They have higher health as well, and now absorb a total of 120 normal damage shots instead.

Almanac entry
Modern=

Brickhead Zombie
Egypt=

Pyramid-Head Zombie
Pirate=

Barrelhead Zombie
West=

Cart-Head Zombie
Future=

Holo Head Zombie
Jurassic=

Overview
Brickhead Zombie and his versions absorb 120 normal damage shots, and their appearance change upon absorbing 37, 74, 110, and 115 normal damage shots before dying at 120 normal damage shots.

Brickhead Zombie
Modern Day: Days 37, 38, 39, 40, 41, 42, 43 and 44

Battlez: Gold Bloom's Garden Party Tournament

Pyramid-Head Zombie
Ancient Egypt: Days 28, 29, 30, 32, and 35

Battlez: Explode-O-Nut's All-Out Tournament

Barrelhead Zombie
Pirate Seas: Days 29, 30, 32, 33, 34 and 35

Battlez: Caulipower's Escalating Tournament

Cart-Head Zombie
Wild West: Days 29, 30, 31, 32, 33, 34, and 35

Modern Day: Day 32

Holo Head Zombie
Far Future: Days 28, 29, 31, 32, 33, 34, and 35

Amberhead Zombie
Jurassic Marsh: Days 36, 37, 38, 39, 40, and 42

Strategies
Brickhead Zombie and his variants can take quite a beating, so resort to instant-kill plants to take them out. Grimrose, which is found in Modern Day, is effective at taking them out, but against groups of them, use area of effect plants like Cherry Bomb, Grapeshot, or Primal Potato Mine. You could also use Primal Peashooters to stall them as they take in damage. Using Shadow-shroom, Hypno-shroom, Caulipower, Chomper, Toadstool, and Chili Bean can help because they ignore their headwear. If you have enough sun for it, you can use a Magnifying Grass to take care of their headwear in a couple of hits. Keep in mind that Magnifying Grass does not do AoE damage, so avoid using it against large groups of them.

General

 * The Brickhead Zombie variants are slightly tougher than Knight Zombie, Blockhead Zombie and Jurassic Fossilhead, and as tough as Mecha-Football Zombie and Disco-tron 3000.
 * The Brickhead Zombie variants have a health close to Robo-Cone Zombie, each one absorbing only 5 NDS less than a Robo-Cone Zombie.
 * Like most veteran zombies, Brickhead Zombies and their variants do not appear in Endless Zones.
 * All Brickhead variants' (except the Pyramid-Head Zombie) Almanac entries start with their first names, which is quite different from other entries since a zombie's Almanac entry will usually start with their pronouns such as "he," "their," "its," and etc. Only plant Almanac entries would usually use a name for the beginning of their entries.

Specific to Brickhead Zombie

 * He, Balloon Zombie, Super-Fan Imp, and Sunday Edition Zombie are the only Modern Day zombies not to appear on Plants vs. Zombies Heroes.
 * His Almanac entry references the classic fairy tale The Three Little Pigs.

Specific to Barrelhead Zombie

 * Barrelhead Zombie's barrel is tougher than Barrel Roller Zombie's barrel, despite the former's barrel being smaller than the latter's barrel.

Specific to Cart-Head Zombie

 * Despite degrading into a basic zombie, he does not dance to Pianist Zombie's music.

Specific to Holo Head Zombie

 * Prior to 6.0.1, when a Holo Head Zombie gets killed by a lawn mower, its force field, arm, and head will fall off separately, but another head still appears to be encased in the force field.
 * The same also happens when killed by plants such as Shadow-shroom, where its arm, head and force field fall off and another head is still encased in the force field.
 * Additionally, when it's killed by explosive plants and Electric Blueberry, it burns into ashes, but it appears to have another head still encased in the force field.
 * This is because Holo Head Zombie's force field sprites have the head inside it.
 * After the 6.0.1 update, though, the force field is in its final degrade when hit by a lawn mower and dropped to the floor.

Specific to Amberhead Zombie

 * His Almanac entry references the movie series Jurassic Park, as in the first movie, a mosquito that bites a dinosaur gets stuck in amber, then many years later, humans found the preserved mosquito and combined the dinosaur DNA inside the mosquito with a frog/toad's and brought dinosaurs back from extinction.
 * When stalled, frozen, or poisoned, its face can no longer be seen inside the amber.
 * Even though Jurassic Marsh already has a zombie with machined protection named Jurassic Fossilhead, another zombie is made with machined protection.
 * The reason of this is that Jurassic Fossilhead is just similar to Knight Zombie and Blockhead Zombie, while Amberhead Zombie is a variant of Brickhead Zombie, who has higher health than the previous four zombies, which are very close to Robo-Cone Zombie's and exactly identical to Mecha-Football Zombie, Disco-tron 3000, etc.