Bug Zapper one of the 9 perks that can be chosen at the beginning of the game on any hero. Selecting this perk gives three effects:

  • You are permanently affected by Empower.
  • Every 8 seconds, you have a 60% chance to fire a single Corona beam and a single Mjölnir Protocol discharge.
  • Your maximum life and shields are reduced by 20%.

Bug Zapper is an effective perk on most heroes, but it is especially effective on front-line tanks like Predator and certain Tassadar builds; all of Predator's damage comes from either passives or spells, so this is an amazing boost to his damage output. The three spell effects (Empower, Corona, and Mjölnir Protocol) can be improved by their relevant upgrades, and all of them are affected by Weapons Research Mastery.

Bug Zapper can also be effective on middle or back-line heroes who are not in the line of fire, as the extra free shots can be used to extend Massacre kill streak bonuses. At present, Bug Zapper is widely considered to be one of the two strongest perks in the game, alongside Air Support. The survivability loss is negligible compared to the continuous damage output.

Bug Zapper has also been covered in part 1 of the official Perk Detail Overview on BlacKcuD's blog, listing some more details on how it works.