Ecto Baa Baa is one of the Ghost Masters (ゴーストマスターズ goosuto masutaazu) that appears in Ghostly Houseguests Event, All Hallows Road and in the Stories of Legend in The Haunted 1LDK.
Enemy
Ecto Baa Baa is the Floating variant of Baa Baa. It's two times more powerful in terms of health and damage, but it is still hardly a threat.