“The missile is purported to be a smaller version of China’s modified Dong Feng 21”
The Dong Feng 21 was named the “carrier killer” because it’s standard warhead is a 500kt nuke. An Iranian version with a conventional warhead ain’t a carrier killer, and a nuclear version just got you into a nuclear war with the USN.
The DF-21D Anti-Ship Ballistic Missile has a guided, maneuvering re-entry vehicle and a conventional warhead.
"Carrier-Killer" is a bit of a misnomer because it would be very unlikely to physically sink a carrier, but it is certainly possible to completely disable a CVN with various types of conventional warheads if they're hitting at hypersonic speeds. A carrier that can't conduct flight ops is a worthless hunk of metal.