Choose any animal from mythology, and explain why you think it could contribute to the functioning of today's society, or offer a capability which would be exceedingly useful in the modern world. Animals can also speak human languages, have a human-hybrid structure, or an almost entirely human appearance while maintaining their unique qualities, if only to fit better into human society.
For me, I would have to say the Nemean Lion, as its near-impenetrable skin would serve well in occupations which might involve possible bodily harm, such as construction, law enforcement, and rescue. The extra strength and the impervious claws wouldn't hurt either.