Origin story
Hanuman, the son of the wind, leapt the ocean to Lanka, found Sita, carried the Sanjivani mountain to save Lakshmana and served Rama with perfect devotion. His strength is always offered in service, never for himself.
The mace is his strength, the mountain is selfless service, and his chest bearing Rama and Sita is devotion itself. Hanuman is honoured on Tuesdays and Saturdays, and his temples in Kerala stand at the edge of villages and in the precincts of larger shrines as guardians of the faithful.
Source: Wikipedia: Hanuman — https://en.wikipedia.org/wiki/Hanuman