"He's a tiger when he's angry" is an example of metaphor.
It's apparently a metaphor for something uncatchable, light of body and fleet of foot.
In present day Japan, "alchemy" is only used metaphorically; to refer to improper means of making money by politicians or religious hucksters with no morals or shame.
This expression has really caught my fancy, as a type of English metaphorical expression not in Japanese.
"A fish out of water" is a metaphor for being unable to use your talents due to a change of environment.