There are two mobs in the game that are (at least intentionally) angry towards (react to) armor stands:

• Zoglins (MC-177122 resolved as WAI)
• Pufferfish (MC-132239 resolved as WAI)

Armor stands can not be broken by these mobs, which is probably intentional, as it would mean armor stands getting broken without player's notice. 

Breaking armor stands requires spam clicking.

However, when mobs try to attack armor stands they do not actually "hit" armor stands, they only try their best - armor stands do not wobble when hit by mobs, but DO wobble when hit by players. 

1) Place an armor stand.

2) Spawn a zoglin and watch it attack armor stand.

3)  Armor stand does not show wobble animation.

What should happen:

Armor stands probably should wobble when attacked by mobs (note that this issue is only related to melee attacks, as any arrow destroys an armor stand) or when pufferfish puffs in responce to it.

Relates to MC-172047 MC-202299 MC-200898