From eggs to crab to ham, that which gives zest to chopped dishes is said to be "deviled."
The term dates back to early explorers who brought to European kitchens red pods of a South American shrub believed to be cayenne pepper. The New World condiment made persons feel as though they were on fire, and so the allusion to hell, and by extension, the devil. Soon the name attributed to the devil's pepper became applied to any spicy dish resembling those that actually used the piquant pod.
Like "full of oats," this stable slang goes back to when horses were fed horse beans, a high-protein food that made the steeds not only frisky but feisty, too. Nowadays, a person who is lively and high-spirited is also considered "full of beans."
SOURCES: 'Why You Say It,' by Webb Garrison; 'Dictionary of Word Origins,' by Jordan Almond.