A green and drooling ogre in fancy dress on a white circle within a blue outer circle with yellow text.
1972 WARREN PUBLISHING CO.
EERIE magazine was a black and white horror comics magazine created in 1966 by Warren Publishing. This button was part of a "Cousin Eerie Fan Club" package available from Warren Publishing's "Captain Company" mail order division (it also came with a fan club card). An example of the magazine advertisement for the fan club can be seen here: http://necronomicondelostemplarios.blogspot.com/2011/06/los-clubes-de-fans-de-warren-publishing.html and here is another example in the pages of an issue of EERIE magazine on Google Books: http://books.google.com/books?id=eoSkbuWxnCgC&lpg=PP1&pg=PA19#v=onepage&q&f=false
The character on the button is called Cousin Eerie and was created by Jack Davis an american illustrator known for advertising art, magazine covers, film posters and comic book stories. He was one of the founding cartoonists for Mad Magazine.