How does the zombies holding pickaxe chance work?
- When the game detects that there is no Pickaxe Zombie (as I call them) in a 50 block radius, it randomly makes two zombies Pickaxe Zombies. This means that wherever you go it will turn at least 2 in a 50 block radius into ones holding pickaxes. I could up this chance in the future, if asked for.

How did you detect the biome the phantoms were in?
- I use an execute store command to store the amount of blocks that any entity is away from a biome (using /locatebiome), if this value is low enough, the phantom is in a Mushroom Fields biome, so we kill it.