The shock rocker — who was one of eight musicians, label heads and recording pioneers welcomed into the exclusive Hall at Manhattan's Waldorf-Astoria hotel — was dressed in what looked to be a blood-spattered white button-down shirt and had his trademark live boa constrictor hung over his shoulders.
"We've always been a hard-rock band," Cooper explained about his group, the Associated Press reported. "We just wanted to decorate it a little differently."
The singer's fellow inductees weren't quite as adventurous with their fashion.
New Orleans piano maestro Dr. John, pop icon Neil Diamond, quirky singer/songwriter Tom Waits and girl-group-era star Darlene Love were the other performers honored on Monday night.
Dr. John, who was inducted by John Legend, said he felt "like I'm blessed to be singing, to be breathing." The two men met back at a benefit for Hurricane Katrina relief, and Legend praised Dr. John for being a leading worldwide voice for New Orleans and its rich, diverse music scene.
"He has never stopped flying the flag of funk," Legend said. "Tonight, he is definitely in the right place at the right time."
Love — who was one of producer Phil Spector's famous "Wall of Sound" voices, fought back tears during her acceptance speech. She was inducted by Bette Midler, who recalled first hearing Love's voice on a transistor radio.
"Listening to her songs, you had to dance, you had to move, you had to keep looking for that rebel boy," Midler said.
Elektra Records founder Jac Holzman, pianist/songwriter Leon Russell and Specialty Records founder Art Rupe also were ushered into the Rock Hall.
The ceremony airs this Sunday 20 on Fuse at 9 p.m. ET/PT.