jdk.internal.misc.Unsafe.park() makes up way too much lag.

[TheProKnightGamer]

The function jdk.internal.misc.Unsafe.park() is a pause function that causes the main thread to wait causing the server to slow.

[Nyfaria]

Report that to mojang.

[RequiDev]

You are using a blocking API multiple times per tick, per entity. This isn't a mojang issue, this is a your code issue.

[TheProKnightGamer]

I was actually looking into a differant angle at the issue, the idea was that the spiders were moving into unformed chunks causing the main thread to wait for the world to load which it isnt supposed to do because its the main thread.

[RequiDev]

You might be correct in your assumption. I've created a PR which does fix the issue on our end: #12