Scowling mobs not attacking.
 

I have noticed in various zones so far, Oasis, and EK just yesterday, that mobs that are scowling at me ready to attack just pass by me.
I would attack screen shots, but I haven't figured out how to take screen shots in game yet.
I have noticed that both the mist wolves and crag spiders in EK aren't attacking me.
And the Crocs in the Oasis weren't attacking.

Actually, none of this is a bug. :)

Crocs in Oasis and Crag Spiders in EK are supposed to be scowling yet not actually attacking people. Here are the patch notes where the devs fixed Crag Spiders, probably based on classic-era evidence people provided. You can probably search around and find the patch notes where they intentionally fixed the crocs to behave the same way.

As for the mist wolves, they are probably green to you. I imagine they will attack if you sit. Unless you are a ranger or druid, in which case they will not attack you.

I suspect this is a lesser-known classic fact. However, do be sure to search these forums for info before making a bug report.

There's history behind this actually.

There was a feature in EQ called "frenzy" that had to be enabled on mobs, it was like a flag that was set on the NPCs in the database, which would cause them to assist each other and to have a chance each tick to attack nearby PCs they were hostile to.

When this feature went live in beta some mobs were missed, intentionally or unintentionally.

They fixed it for a few days on Live after launch in Spring of 99 by enabling 'frenzy' on crocs, in that yes, crocs in Oasis would actually attack you and assist each other, but then they got so many complaints that they changed it back and just left it off.

Anyways, classic bug-that's-actually-a-feature.

Death beetles in Unrest are the same way.

If I recall correctly, the ogres in West Karana had the opposite situation. They would /con as non-KOS but would actually attack on sight. I'm not sure if P99 has that "feature."

You’re describing the friendly rallos zek ogres that simply assisted the aggressive chief goonda (who has a large attack radius). It was often mistakened that they were kos because of this.