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Jake "The Snake" Roberts has a very serious battle to fight outside the ring. Doctors recently discovered that the WWE legend, 58, has a cancerous growth behind his knee which requires emergency surgery, he told TMZ on Sunday, Feb. 23.

Jake (real name: Aurelian Smith, Jr.) discovered the growth last month, with tests confirming last Friday that it's cancerous -- and growing into his muscle. The surgery is scheduled for this Tuesday, and Jake vows to return to the ring at the Jersey Championship Wrestling match on March 13.

"If the devil can't defeat me, cancer doesn't stand a chance in hell! Pray for sick children who face this horrible disease 'cause The Snake will be just fine," the WWE Hall of Fame 2013 inductee tells TMZ.

Jake first made a name for himself in the WWF in the late 1980s during the heyday of the performance sport.