I have reported this issue before but was told the information was incomplete. Here is the old link: MCPE-123207

The problem is, please look at the way the zombie held the trident when he is attacking, it seems like he is using the end of the trident to stab the zoglin, which looks funny.

How to reproduce: Just give the zombie a trident, he may pick it up and hold it in his hand, then spawn a zoglin beside him and they will soon in fight, and you will able to see the scene.