Myconid Trader Shifting into Bears?

[granny]

Ok... this is really funny. The Myconid Trader of Mycopolis is now a bear (some hideous hag work probably, no, not mine!)... and it's running from us.

Not sure if it's related but I was shifted into a bear earlier.

[AllMYBudgies]

It does this when it's attacked in some way - perhaps by an AoE spell effect or by summoning a hostile npc through a variety of means.

It's also not a bug, it's simply defending itself the same way that all NPC's do.