Bobby "Boris" Pickett made quite a living from that song. He was still performing it decades later. Here is a 1992 performance of it. Also, Bobby recorded a Christmas version of the song called "Monster's Holiday" which was a minor hit but appears on many 1960s Christmas compilations of which I had a few.
The song never made him fabulously wealthy however. By the early 1970s, he was a taxi cab driver in NYC, if you can believe that. But shortly thereafter, the song re-charted and Bobby was in demand pretty much every Halloween thereafter, finally passing away in 2005.
If he had the money to obtain an NYC cabbie medallion and a secure gig, he didn’t do too bad at all!