+5 bombs. Isaac's bombs will now explode in a large cross-shaped pattern (roughly 5 bombs explosions wide). This also affects player-spawned Troll Bombs.
Grants 5 bombs.
Causes bombs to explode in a large cross-shaped blast by adding two additional explosions in each cardinal direction.
The damage for a single explosion is unchanged, but each successive explosion that hits the same enemy has its damage halved; for example, if 5 of the explosions hit the same enemy, the total damage is 60 + 30 + 15 + 7.5 + 3.75 = 116.25 instead of 60 * 5 = 300.
Mr. Mega changes the base damage to 110, with the same halving reductions as above.
Dr. Fetus - Bomber Boy also affects the bombs fired by Dr. Fetus.
Mr. Mega - All explosions deal more damage, have a larger radius and will overlap each other more, potentially vastly increasing damage. Caution should be exercised, as the explosions' increased radius make self-damage likely.