Roger Crab (1621 – 11 September 1680)[1] was an English soldier, haberdasher, herbal doctor and writer who is best known for his ascetic lifestyle which included Christian vegetarianism.

Crab fought in the Parliamentary Army in the English Civil War before becoming a haberdasher in Chesham.

[3] At the outbreak of the English Civil War in 1642, he joined the Parliamentary Army under Oliver Cromwell.

He built up a practice as a herbal doctor, advising his patients to avoid meat and alcohol.

[6] Crab held the unorthodox view that meat-eating was the cause, rather than a consequence of, the Biblical fall of man.

[7] By the age of 20, Crab was living on a diet of vegetables and water "avoiding butter, cheese, eggs, and milk."

Crab argued that "eating of flesh is an absolute enemy to pure nature" and believed there was a connection between meat-eating and aggression.

[10] His tombstone has the following epitaph:[11] Tread gently, reader, near the dust Committed to this tomb-stone's trust: For while 'twas flesh, it held a guest With universal love possest: A soul that stemmed opinion's tide, Did over sects in triumph ride; Yet separate from the giddy crowd, And paths tradition had allowed.

Christopher Hill suggested that Crab may have been the inspiration for Lewis Carroll's character the Mad Hatter.