So I recently started up Minecraft again, and while I have been keeping up to date with all the big updates, I haven't been quite so involved to follow the finer details.
During a recent session, I came under attack of the usual beasties, but one appeared to be actually invisible! I was being attacked by... something... And I only got a glimpse of maybe some very faint eyes... I swung in that general direction, and eventually whatever it was, stopped.
Later, I came across another spider, which appeared to have particle effects surrounding it. I don't know what it was, or how it affected the spider, but at that point I wondered, maybe the invisible creature from earlier was perhaps a spider as well.
Is this a thing? Can spiders have different effects applied to them, and (outside of throwing a potion at them), how do they gain these effects?