Originally posted by Handlampe:

I started a few days ago a new single player world.
I played ist since release as single player until bonemass,
i played it with some guys on dedicated server...even into mistlands...
no problem!
In my new single player world i reached Moder... But on the spawn of moder are also 3!!!! spawns of golems! i cleared it up! even the dragons and wolves!
On the next morning i activated Moder and got ♥♥♥♥♥♥ up by respawning golems, wolves and dragons during fighting Moder...i got Moder down to 70% but get killed by respawning ads.... wolves, dragons AND golems...
Sorry this can't be serious...

It is all just random.

How to deal with respawns near boss fights:

Dig pits outside of the boss arena but not to far away. Drag mobs with the harpoon into it. If there are mobs around there are no rewspawns.