Set was a sky-God like Horus, but specifically of the storm, with lightning and thunder as His heralds.

Eventually Set's reputation changed, because of His natural opposition to His brother/nephew Horus, and because, during the Second Intermediate Period, the Hyksos invaders identified Him with their own god.

In the New Kingdom Set became the "Lord of the Desert", the Red Land which crept into the arable land at the end of each year and was therefore thought of as the "murderer" of the Lord of the Black Land (Osiris). Set became literally demonized, and in late periods was identified as a symbol of complete destruction.

Later, the God influenced other religions' concepts of the "Devil," including both the Greek Typhon and Hebraic Satan. It is important to note that both are non-Egyptian concepts. Set at all times, while not exactly a "nice guy," is a necessary force in the universe - that of strength and violent force - and in Egyptian myth, even Ra acknowledges this, by awarding the post of "Guardian of the Boat of Millions of Years" to Set after the kingship is given to Horus, because Set "is the only one strong enough to do it".

Set is symbolized by the scorpion and the pig, and sometimes the jackal. His main theophany however is an unknown canid with square ears and a forked tail, often called simply the "Set-animal," whose species has been a mystery to Egyptologists. In late 1996, a large mammal with square ears and a forked tail allegedly was caught and killed in Upper Egypt. Called salawa by the locals, the animal appears to be related to the South African Cape Hunting dog. Its extreme size and appearance lend credence to the folk tales surrounding this rare desert mammal as "Set."