I don't suppose the engraver has a grudge?
Nope; the leader counts as 'friend'. Maybe it's an inside joke on their part?
I had him engrave some tiles of the leader's tomb and sure enough, there's an image of cave spiders. Both the tomb and the office were designated rooms beforehand.
Also, some more updates on engravings in the new version...
The 'battles never witnessed' engravings involve two different humans, one of whom was mortally wounded by a giant desert scorpion which he later killed, and the other one who slew about three named nightwings before being killed by a named jaguar. It seems that the engravings for battle are much more complex than I thought, though, since some of the engravings seem to give a blow-by-blow account of the actual battle as it proceeded. I've seen things like:
Raji Trampledacts is cringing. Feddwellers is striking a menacing pose. The artwork relates to the smashing of the human Raji Trampledacts's third toe, left foot by the nightwing Feddwellers in 222.
and
Fatab Lordgerbil is in a fetal position. Ancientsavior is laughing. The artwork relates to the ripping of the human Fatab Lordgerbil's lower body by the giant desert scorpion Ancientsavior in 244.
I always figured the 'fetal position/laughing' combination and the like all referred to the actual killing, but apparently not!
The only engraved beast that hasn't been killed by one of the heroes is a giant jaguar called Empireleaves, but I haven't seen him loping around the desert so maybe it died from its wounds. (If something else had killed it, it seems like my dwarf Seer-Engraver would know
)