What does "with your horns up" mean in this sentence?

It’s in your nature to read self-help books like this with your horns up, ready to pounce on any idea you think is flawed. It’s easy to be a cynic. It requires no energy to be skeptical or negative.

I tried to search this on dictionary and google, but no accurate result found.

with one's horns up = in an aggressive or beligerent mood, ready to attack.

This has nothing to do with the Devil. It is figurative and based upon the attack method of a bull or other horned animal.

I saw a huge gaur[1] rushing out of a thick bamboo bush to attack us. It was less than 10 meters from me and I did not have time to raise my gun. Head down, horns up, he attacked in a lightning rush forward, his huge feet stomping the ground like thunder. Brushing the World Famous: The Story of My Life by Hanh Nguyen

[1] https://en.wikipedia.org/wiki/Gaur

The most famous popular gesture of recent years, the V for Victory sign popularized by Sir Winston Churchill, seems to be a horns-up sign, implying the power of a horned animal. Man, Myth & Magic: An Illustrated Encyclopedia of the Supernatural, Volume 8 (1970)