Hostile mobs on vanilla

[XAngelGiirlX]

So a friend of mine and I have been playing on the vanilla survival server for about a week now and there are a few things we had noticed:
-Hostile and neutral mobs (and bats) do not spawn in the overworld whilst hostiles in the Nether do spawn;
-When hostile mobs spawn from a mobspawner, the mobs freeze and do... well, nothing;
-I can't seem to find any natural desert, savannah and mesa biomes (but that may just be pure bad luck).

Although it's fine, not being bothered by hostile mobs, it does take away from a bit of adventure you are expecting from survival.
Can this be fixed? If it can be, please do so. We would really appreciate that and enjoy our experience on the Craftland vanilla survival server even more.

[nidefawl]

Thanks a lot for reporting.

I will fix this next time I work on vanilla.
Vanilla isn't top priority tho