I found the point where things went awry in the gamelog. I'm pasting a snippet below.
I was running Ironhand 0.73 and using the spintermind-attributes version of Therapist. I tried DFHack out once but to my knowledge I didn't make any permanent changes to the game itself. I'm pretty sure I genned that world after removing DFHack.
Fortress mode had a good run, and ate way too much of my time. I'll give Adventure mode a try now....
LOG:
The Stray Cave Crocodile latches on firmly!
The Stray Cave Crocodile shakes The Dog around by the left rear paw and the severed part sails off in an arc!
The left rear paw is ripped away and remains in The Stray Cave Crocodile's grip!
Cog �blelr¡t, Farmer cancels Pen/Pasture Large Animal: Interrupted by Stray Cave Crocodile.
Vab“k Thimshurcatten, Miner cancels Store Item in Stockpile: Interrupted by Stray Cave Crocodile.
Dod¢k Zatkol, duchess cancels Store Item in Stockpile: Interrupted by Stray Cave Crocodile.
The Hammer Lord bashes The Stray Cave Crocodile in the right front leg with his (-®+steel war hammer+¯-), chipping the bone!
The Hammer Lord bashes The Stray Cave Crocodile in the left front leg with his (-®+steel war hammer+¯-), chipping the bone!
Eshtƒn K–buks rek, Diagnoser cancels Eat: Interrupted by Stray Cave Crocodile.
Lokum Nalmedtob, Elite Marksdwarf cancels Eat: Interrupted by Hammer Lord.
The flying {cave crocodile bone bolt} strikes The Hammer Lord in the upper body from the side, tearing the muscle and tearing the liver through the steel breastplate!
The {cave crocodile bone bolt} has lodged firmly in the wound!
The Miner punches The Stray Cave Crocodile in the right front foot with her left hand, bruising the muscle!
The Mace Lord bashes The Stray Cave Crocodile in the right front leg with her ð®ðsilver maceð¯ð, chipping the bone!
Catten Sefolrig•th, Fish Cleaner cancels Store Item in Stockpile: Interrupted by Stray Cave Crocodile.
The Swordmaster stabs The Stray Cave Crocodile in the right rear leg with his iron short sword, chipping the bone!
A tendon has been torn!
•nul Akgoslokum, Brewer cancels Store Item in Stockpile: Interrupted by Swordmaster.
•nul Zithisudil, Armorer cancels Store Item in Vehicle: Interrupted by Swordmaster.
Kad“l Geshudzat, Strand Extractor cancels Extract Metal Strands: Interrupted by Swordmaster.
The flying {ðcave crocodile bone boltð} strikes The Swordmaster in the lower body from behind, but the attack is deflected by The Swordmaster's steel breastplate!
The flying {cave crocodile bone bolt} strikes The Hammer Lord in the right lower leg, chipping the bone through the ðsteel high bootð!
A ligament has been torn and a tendon has been torn!
The Hammer Lord gives in to pain.
Dumat Thobasrer, Stonecrafter cancels Place Item in Tomb: Interrupted by Swordmaster.
The Swordmaster strikes at The Miner but the shot is parried!