In the Hercule Poirot novel Five Little Pigs, Amyas Crale was a forty year old painter and the husband of Caroline. He had many affairs despite being married to Caroline Crale and had a passionate, high-handed and arrogant personality.
According to Phillip Blake, Amyas was "one of those people that don't usually have health problems".
He was poisoned with coniine while painting.
Role in the novel (warning; it may contain several spoilers)
He had been asked by twenty year old Elsa Greer to make a portrait of her. Amyas didn't regularly paint people (as Sir Montague Depleach noted: "Amyas didn't paint subjects like 'Mrs Blinkety Blank in satin and pearls'") but he made an exception for Elsa. Due to this, the latter thought that Amyas was going to leave his wife and marry her. However, when Elsa realized that Amyas didn't have such plans, she stole coniine from Meredith Blake's laboratory and poisoned his beer.