This is a seal from the book "Lesser Key of Solomon". According this text, the spirit Bael, is described thus
"The First Principal Spirit is a King ruling
in the East, called Bael. He maketh thee to go
Invisible. He ruleth over 66 Legions of Infernal Spirits.
He appeareth in divers shapes, sometimes like a Cat,
sometimes like a Toad, and sometimes like a Man, and
sometimes all these forms at once. He speaketh hoarsely.
This is his character which is used to be worn as a
Lamen before him who calleth him forth, or else he will
not do thee homage."