In Minecraft, players can get special items called mob heads. These are small blocks shaped like the heads of certain mobs.

Minecraft mobs drop all sorts of loot, some of which are pretty valuable. A lot of them drop food or other useful crafting, so it's a good idea to farm them.

Need XP fast in survival? This tutorial shows you how to build the easiest mob XP farm in Minecraft 1.21+ — no spawner ...

Minecraft Bedrock Edition players can edit their world settings under “Game” and uncheck the box next to “Mob Spawning.” Java Edition players can type “/gamerule doMobSpawning false ...

To control mobs in Minecraft Legends, players can either have them rally, send them to charge forwards, or focus on specific targets.

Control your mobs in Minecraft Legends Every command has a name, specific control, and end result that the mobs will perform if they are close enough to you.

Though not verbalised it certainly looks like that means you will be making an army of mobs to fight against The Nether. Classic Minecraft stuff with a whole new look.