Thanks for passing that message along.
Imgflip isn't the place for posting or reposting about raping a child.
Federal laws protect minors from threats through statutes covering conspiracy against rights (18 U.S.C. § 241), threatening/harassing communications, extortion, solicitation (like sextortion via 18 U.S.C. §§ 2422-2423), and using minors in crimes, with penalties escalating for offenses involving children, especially sex crimes.
I found the original comment, the username(s) involved and will pass that info along.