Venus Magnum

The Venus Magnum is a gun that is only dropped by the Hardmode boss Plantera. Arguably, it can be better at killing bosses in comparison to the Megashark, but is much more bullet-consuming due to not having an innate ability to save ammo. When ammunition isn't a priority, it may be better to use this over the Megashark due to its significantly larger base damage. The only downside is that it is semi-automatic which makes it more difficult to use to its full potential, compared to other hardmode weapons.