Amdusias is a demon king with 40 legions of demons under his command, according to the Ars Goetia of The Lesser Key of Solomon. He is depicted as a human with claws instead of hands and feet, the head of a unicorn, and a trumpet to symbolize his powerful voice. According to other sources, this demon is depicted as a unicorn, and changes into a man under the request of the conjurer.
Amdusias is associated with thunder and it has been said that his voice is heard during storms. In other sources, he is accompanied by the sound of trumpets when he comes and will give concerts if commanded, but while all his types of musical instruments can be heard they can't be seen. He is regarded as being the demon in charge of the cacophonous music that is played in Hell. He can make trees bend at will.
He is also mentioned as a King in Johann Weyer's Pseudomonarchia Daemonum (1583).