Dr. Terror arrives twice each week in Boom Beach, once at midnight GMT on Wednesday (that’s 8 pm ET on Tuesday for East Coasters and 5 pm PT Tuesday for West Coasters) and once again on midnight GMT on Saturday. If you have alerts enabled on your device, you’ll get a message that he’s landed.
You need to have already defeated Lt. Hammerman’s Level 10 Base to get Dr. Terror on Wednesday and you must be Lt. Hammerman’s Level 20 Base to get Dr. Terror on Saturday.
When Dr. Terror arrives, there are a series of 20 different stages and they change each time. Each stage gets progressively harder, meaning you’ll need to be fairly high level in the game to defeat the later stages.
In the early days of Boom Beach, it was often possible to beat all the stages with a Warrior Rush technique, but lately the stage design, along with recent changes to Warriors, have rendered this strategy much less effective.