The world's most gruesome murderer is Ed Gein who would flay (knife off their skin) them and make their skin into a mask.
The world's most gruesome killer is debatable; could be Josef Rudolf Mengele, could be Pol Pot, could be Vlad Țepeș, could be Countess Elizabeth Báthory de Ecsed, and there are any number of infamous historical figures who could stand in the ranks as the most gruesome killer.
The pile of corpses left by the serial killer was a gruesome sight.
keiko(willy) was the worlds most famous killer whale
michael myers
Hitler
Shamu Is The Stage/Last Name Of The Killer Whales At The Three Sea Worlds. Killer Whales Are Actually The Largest Species Of Dolphin, Being Called Killer Of Whales, But Was Then Changed To Killer Whale, As They Will Kill And Eat Most Things, Even If They Are Bigger Than They Are. At The Sea Worlds, They Are Often Called Orcas, As Their Latin Name Is Orcinus Orca.
Nathan Ximenez
Jeffrey dahmer
rip him to pieces and burn him that would be so cool and gruesome
Ebola or Necrotizing Faciitis
The worlds largest bony fish is the Actinoptergyii.
The black widow. Can kill ya in 4 hours
a mini