When Brook came face to face with Big Mom, he was truly terrified at seeing one of the Four Emperors, whereas Big Mom was very interested in Brook being a living skeleton. During their fight, Big Mom overwhelmed him and soon questioned Brook's motives before ridiculing his optimism.
1 Yomi Yomi no Mi
A major selling point of Big Mom's Devil Fruit is its ability to extract souls and turn them into Homies that are seemingly indestructible. Brook, however, has manipulation over his own soul because of his Devil Fruit, and he can project it to overpower the Homies.
TL;DR Big Mom is afraid of Shanks because he's just too powerful for her.
In contrast to the other cowardly crew members own fears - Usopp's being out of insecurity, Nami's as a survival instinct, and Chopper's from cautiousness - Brook's fear is more down to Earth; he fears the things that are not normal.
We recently learned that big mom's weakness is a photo of someone named Mother Caramel, and that even slight damage to it causes her great physical pain and somehow makes her skin thinner.
1) Shanks. Without a doubt, Shanks is one of the most overpowered characters in all of One Piece. Shanks, like Big Mom used to be, is one of the four Emperors of the Sea, meaning that even the World Government acknowledges his power, and with good reason.
One Piece 1079 confirmed that Shanks is much stronger than Big Mom.
Even Zoro has quietly acknowledged that Brook is a true man to his heart, facing down odds that are near impossible unflinchingly to save a friend. As possibly the ultimate example of this, he shows absolutely no fear in the face of Big Mom, an Emperor, who is specifically able to use an opponent's fear against them.
Due to his lack of flesh, Brook is resistant to lightning strikes and high and low temperatures. He is also immune to Caesar Clown's Shinokuni gas. Brook does not age, as his body only consists of bones, and he continues to grow stronger despite being 90 years old.
He does seem immortal as we have seen him be beheaded and damaged several times, from which he had healed back by drinking calcium rich drinks such as milk. The only two possibilities there are to killing him is by either submerging him into water or by crushing his entire body forcing the soul to leave the body.
Among her many children, Big Mom appears to have favorites. Pudding is one such child, due to her tremendous acting skills and also her third eye, which has the potential to read the Poneglyphs.
10 Jinbe Wasn't Scared Of Big Mom Or Any Other Yonko
Surprisingly, Jinbe didn't even flinch in her presence and declared that a mere Yonko would never be able to frighten him.
Katakuri is the strongest Sweet Commander and also the person Big Mom trusts the most. Before his fight against Luffy, Katakuri had never once lost a fight. Katakuri is also a user of the Paramecia Mochi Mochi no Mi devil fruit and masters all three types of Haki.
Brooke is the only character in one. Piece who can defeat Blackbeard. brooke's Revive. Revive Fruit lets him remove souls from a body.
His story with the Yomi Yomi no Mi
With the Yomi Yomi no Mi, Brook cannot die. One day, there was a storm that hit his ship. It killed all of his crew, including Brook. But because of the Yomi Yomi no Mi that he consumed, Brook came back to life.
9 Brook, The Musician
With his sword, he can summon the cold of the underworld and freeze all those in his way; however, he's still far from the strongest in the crew.
He isn't immortal, he said that in an earlier chapter, his body has to be destroyed for him to die. The power is to be reborn ONCE and only once, so a second death results in complete death.
Also, due to the Devil Fruit powers allowing it, Brook has the ability to store objects in his skull by opening it along its crack. While Brook is able to do these things because of his Devil Fruit supported form, he however can still feel pain, as well as fatigue.
It was later revealed that Brook had no reflection or shadow. Brook explained that his shadow was stolen, though refused to say by whom out of regard for the Straw Hats' safety. Because of this, he could not go out into the sunlight or else he would disintegrate like a similar person who had also lost his shadow.
When he was a child, he was afraid when Garp would find out about his dreams of sailing as a pirate. He is wary of Nami's temper, as he thought whoever wanted to marry her is brave.
Can Big Mom take Brooks lifespan? If the person shows fear for even a moment, Big Mom will be able to take their lifespan in any amount that she chooses, even their entire remaining lifespan, killing them instantly.
In terms of pure strength, Kaido is stronger than Big Mom.
Rayleigh is a user of all three types of Haki. He can also use Advanced Armament Haki and Observation Haki. Even in his old age, Rayleigh is a match for the strongest fighters in the series.
Dragon would have a tough time beating her and maybe suffer some serious injuries but he could beat her.