Updated:

1. Summon a giant (Java)

/summon giant ~ ~ ~10

A zombie about 12 blocks tall. It has no AI, so it never moves or attacks. Bedrock has no giant.

2. Huge zombie that attacks (Java 1.20.5+)

/summon zombie ~ ~ ~10 {attributes:[{id:"minecraft:scale",base:5}]}

Use minecraft:generic.scale on 1.20.5 to 1.21.1. See the attribute command.

3. Zombie that does not burn (Java)

/summon zombie ~ ~ ~5 {equipment:{head:{id:"minecraft:leather_helmet",count:1}}}

Any helmet stops sunlight burning, though it slowly loses durability. Use ArmorItems on 1.21.4 and earlier.

4. Armor and weapons (Java 1.21.5+)

/summon zombie ~ ~ ~5 {equipment:{mainhand:{id:"minecraft:iron_sword",count:1},chest:{id:"minecraft:iron_chestplate",count:1}}}

For tougher mobs see the boss mob command.

5. Door breakers (Java)

/summon zombie ~ ~ ~5 {CanBreakDoors:1b}

They break wooden doors on Hard difficulty.

6. Husks and drowned

/summon husk ~ ~ ~5
/summon drowned ~ ~ ~5

Husks do not burn in daylight and cause hunger. A zombie that stays underwater for about 30 seconds becomes a drowned, and a husk underwater becomes a normal zombie.

7. Baby zombies and chicken jockeys (Java)

/summon zombie ~ ~ ~5 {IsBaby:1b}
/summon chicken ~ ~ ~5 {Passengers:[{id:"minecraft:zombie",IsBaby:1b}]}

Baby zombies are small and fast, good as pests in parkour or PvE maps. The second line is a chicken jockey. See baby mobs for other mobs.

8. Summon and cure a zombie villager

/summon zombie_villager ~ ~ ~5
/effect give @e[type=zombie_villager,limit=1,sort=nearest] minecraft:weakness 30 0

Give it Weakness, then use a golden apple on it, and it turns back into a villager after a few minutes with cheaper trades. Full steps are in the zombie villager cure guide.

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