Slimes, magma cubes, pufferfish, and ender dragons can consume the durability of shields within seconds

The Bug:

Slimes, magma cubes, pufferfish, and ender dragons can consume the durability of shields within seconds.

This most likely has something to do with how these mobs have little to no attack cooldown.

Steps to Reproduce:

1. Summon a large slime by using the command provided below.

   /summon minecraft:slime ~ ~ ~ {Size:4,Attributes:[{Base:0.0d,Name:"minecraft:generic.movement_speed"}]}

1. Switch into survival mode, obtain a shield, start blocking with it, and slowly approach the slime.
2. Wait for it to begin attacking you.
3. Look at the durability of your shield closely.
4. Take note as to whether or not slimes, magma cubes, pufferfish, and ender dragons can consume the durability of shields within seconds.

Observed Behavior:

Slimes, magma cubes, pufferfish, and ender dragons can consume the durability of shields within seconds.

Expected Behavior:

Slimes, magma cubes, pufferfish, and ender dragons would not be able to consume the durability of shields within seconds.