I loaded up my file and immediately started moving. After I moved a couple tiles, Damaos interrupted me to remind me the library exists. My creatures somehow separated from me (the cat) and decided to travel diagonally through walls.
Just before this, I had returned from a realm and started moving immediately upon loading into the castle, and my lead creature decided to strike off on his own and try to tunnel through the plant to the south of the warlord. I didn’t grab a screen shot of that one.
Pretty sure this is just a harmless glitch, but hey, a bug’s a bug.