Goat-headed Butlers

They are the faithful servants of Beatrice, and their primary weapon of choice is a sword. Their physical strength is enormous but they lack the intelligence to do anything but faithfully follow orders. Of all the beings summoned by Beatrice, their rank is the lowest, and they can be killed by being shot in the head.

[Spoiler] They seem to be quite ravenous when eating, judging from how horribly mangled their victims become. In 'Twilight of the Golden Witch' they are ready to eat whatever comes their way, willing to chew away the whole island. It is later revealed that they are the personification of random opinions in the future, and all of them want the island's tale to be a tragedy. According to Erika, the goats keep getting born from the sea of the internet. In total, they number in the hundreds of thousands.

(Source: Umineko No Naku Koro Ni Wiki) [/Spoiler]