The BFB is a massive Bird exclusive to the Hamlet DLC. It appears every 10-24 days, heralded by a loud cawing, and then a large shadow flying above the player. It is an extremely large bird creature that has foliage growing on it, with two extra "inner" heads inside its beak. It is a source of Dung Piles, dropping a few as it flies around. The Dung Piles do NOT deal damage to the player, despite showing a visible shockwave-Like effect.
The BFB will start flying above the player and its shadow can be shown, getting closer and closer to the ground. Depending on the turf the player stands on, the BFB can land or keep flying above the player.
After gradually flying closer, the BFB will land when the player comes into contact with the shadow of its torso. Upon landing, the BFBs head will start follow the player and start walking in that direction, Its feet, similar to Bigfoot, will deal 1000 damage if they step on the player or nearby mobs, will destroy buildings and cut down trees. If there is a structure (and Gnat Mounds) near the head, it will stop chasing the player to bop its head on it to destroy it, dealing 1000 damage. BFBs head moves pretty much as fast as a normal player, so it can be outrun with speed boosts like a Stalking Stick, Walking Cane or Coffee. If the BFB catches up to the player, it will carry it to its Nest and drop it off unharmed, leaving them to explore the Pinacle. One of the things in the nest is a Stone Egg which hatches into a Ro Bin.
The BFB can also be summoned at will by using the Bird Whistle.
The BFB will not spawn during Night, Full Moon or the Aporkalypse, and will fly away immediately after landing if summoned with the Bird Whistle.
It was added in the Early Access of Hamlet. It was not fully implemented in the closed beta, but it could be debugspawned.
At the end of the Hamlet E3 trailer, a large bird-like silhouette that slightly resembles the BFB is shown flying in the distance.
The name "BFB" may be a reference to the Roald Dahl book The BFG, which stands for "big friendly giant". "BFB" may then stand for "big friendly bird".
The fact that the BFB takes the character to its nest also may refer to The BFG, in which the giant takes a girl to his home in order to keep her from telling other humans about the existance of giants.
The name may also be a referece to the BFG, a large weapon in the Doom video game franchise.
If you turn off BFB and then in game use bird whistle, he will still spawn.
The BFB's original name, (as seen in the Hamlet early access announcements) was "The Roc". Its prefab name also remained "roc". A Roc is a giant legendary bird from Middle Eastern mythology.
The BFB's legs act quite similar to Bigfoot - with the same amount of damage.
Its design may be based off of the shoebill stork. Having a visually similar head, legs, and posture.
When raining, the BFB's shadow will provide shelter, granting 35% Wetness resistance, and preventing held Torches from being affected by Rain.
The BFB will still do the flyover sequence when spawned with the console.