The phrase "rogue elephant" describes an elephant that behaves aggressively or unpredictably, often causing damage or posing a threat to people and other animals. Full definition
From saving Baghdad zoo to rescuing rogue elephants, it's no wonder Hollywood is planning a film about maverick conservationist Lawrence Anthony (newscientist.com)
Enviros praised Huntsman as the heroically rogue elephant. (grist.org)
This failing is a serious one, though not, in my mind, the sort of failing that should call forth Bishop Wright's suggestion that an «angry superpower, like a rogue elephant teased by a little dog, has gone on the rampage stamping on everything that moves in the hope of killing the dog by killing everything within reach.» (firstthings.com)