Source: Feast of Dust, pg(s). 63
Shaghals are less intelligent than humans, but enough to understand complex commands and work with others to hunt prey. They cannot speak, but understand fiendish speech, and those that communicate with them via telepathy receive morose, fatalistic responses. Shaghals spread disease, hunger, death and savagery wherever they go, and only wish to partake in ruin.
Shaghals are most commonly found roaming in packs across the wastelands of Abaddon. They are sometimes summoned to Material Plane deserts, where they intimidate jackal packs into submission. Under command of a shaghal, jackals become significantly more confident, enough to take over settlements and oases to terrorise humanoids. Shaghals falsely believe that the souls of their victims are directly sent to Abaddon.