Dharma protectors, also known as Dharmapalas, are deities in Buddhism who safeguard the Dharma (Buddhist teachings) and practitioners from obstacles and threats. They can be emanations of Buddhas or Bodhisattvas, or powerful worldly beings who have taken vows to protect the Dharma. 

Dharma Protector Day

A Dharma Protector is an emanation of a Buddha or a Bodhisattva whose main functions are to avert the inner and outer obstacles that prevent practitioners from gaining spiritual realizations, and to arrange all the necessary conditions for their practice.