Shulkers Teleport from Snowballs and Eggs

When below half health, shulkers will teleport when hit by thrown snowballs and eggs

Steps to reproduce:

• Go up in the air so that no blocks are within about 25 blocks of distance
• Build the setup shown in the attached image. Make sure the shulker has glass all around it except for the trapdoor
• summon a shulker in the location shown using the command /summon shulker ~ ~ ~ {Health:14f} or a similar command
• use the command /data get entity @e[type=shulker,limit=1] Health to confirm that the shulker's health is 14
• spawn multiple snow golems in the location shown
• wait for about 1-2 minutes for the shulker to teleport away from its original spot
• verify that the shulker still has a health of 14 using the command /data get entity @e[type=shulker,limit=1] Health

A similar process can be used with eggs, either using a dispenser on a clock or the player.

Expected: shulkers do not teleport from snowballs or eggs, since the shulker does not take damage from them

Observed: shulkers treat snowballs and eggs as a form of damage and teleport because of them