Bödvarr and Bile Troll have exhibited this behaviour where they will do damage (attack) without showing an animation for it. I have attached videos of those two examples as it’s hard to explain what happens exactly.
Reproduction Rate (Choose One):
Rare (< 10%)
Console log from Bile Troll incident:
console-2018-12-20-14.01.42-38D16C75-D4B0-4B00-8B59-8254.log (410.6 KB)