Sometimes, BBF can even damage you as soon as you enter a room! Bob's Brain, at least, was toned down a bit in Afterbirth, as it now can't be fired for a few seconds after it spawns or after you enter a room, preventing surprise explosions.

What makes them divisive is that they have a tendency to respawn as you're firing your tears on close-quarters there's nothing worse than having them respawn and explode on top of an adjacent enemy, catching you in the blast. The latter is a friendly Boom Fly that bounces across the room, exploding on contact with an enemy. The former is an explosive projectile familiar that you can fire at enemies for poison damage. As such, picking up Host Hat or Pyromaniac to No-Sell the explosions from these items is recommended: Generally speaking, most passive items that cause explosions that you can't control are looked down upon by the community, due to the fact that their blast radius can easily damage you.