[16:33:06] [Server thread/WARN] [Respawning Animals/]: Mismatched spawn type for alexsmobs:crocodile! Mob is registered as WATER_CREATURE, but spawning as CREATURE. Report this to the author of Alex's Mobs at
https://github.com/Alex-the-666/AlexsMobs/issues.

Saw this too. I imagine this is why I am having crocodiles randomly spawning in my mine at Y-57