Goats attack armor stands that are used in map making. 

Same also applies to Zoglins and Pufferfish: see MC-205797 and MC-206560.

Reproduction:

• Execute the following command /summon armor_stand ~ ~ ~ {Marker:1b}
• Spawn a bunch of goats
• Wait for them to attack the Marker armor stand

Even players cannot interact with these, but goats try to.

Please note that it only applies to armor stands with a Marker tag, and not the new Marker entity!