The Guru is a character that appeared in Sly 3: Honor Among Thieves.
The Guru is shamanic spiritualist that resides in Australia. When Murray went his separate way after Sly 2: Band of Thieves ended, he ended up going to The Guru and was taught the arts of the Dreamtime course, thus making The Guru his spiritual master.
The Cooper Gang first encounter The Guru during their trip to the Australian Outback. They find out that the miners have overrun the region and stolen The Guru's Moon Stone and staff. Upon successfully getting these items back, The Guru joins the Cooper Gang in their missions, as well as helping Sly get into the Cooper Vault in the final job.
After the events of the game, The Guru decides to take on new students for his Dreamtime course. However, some unwanted attention was attracted and he was incredibly annoyed by this, moving to New York to get away from everything. The Guru does not speak English and despite the player not knowing what he says, all other characters in the game understand him.