Titanic Bomber

Titanic Bombers are potentially the most dangerous Mini-Boss you could encounter. They start appearing on Wave 40+, and are a signal to the beginning of something terrible. They carry HUGE bombs and target the Core only. There is also a Bomb indicator and warning sound on spawn, so you know where the unit is. There can only be 1 Titanic Bomber on the map at once. You should prioritize killing them first, as they could also pose as a meat-shield for weaker zombies to pass through and damage the Core enough for the Titanic Bomber to dismantle the Core in one blow. Titanic Bombers have 7500 HP and 10 Walk Speed, making them fairly manageable for the time that the Unit is walking to the Core.

If you are playing on the first map, then always look out of the front and target the Titanic Bomber first. Then focus on any other mini-bosses, siege or infantry. The map is always linear so you will be able to kill him fairly easy. If he manages to get to the gateway then say goodbye to half of your Core HP.

If you are playing on the second map, then get around the labyrinth quickly to the gate that the unit spawned at. You won't have much time before they spawn for them to get to the Core, as the map is very small, ranging only 1000 studs.

If you are playing on the third map, then you should have tons of time to deal with him. If he spawns anywhere that isn't the Front Middle, Bottom Left or Bottom Right gates, then you're good. You could easily take him out before he makes it to the Core, no doubt. If he spawns at the Front Middle, then he will just walk straight, giving you enough Railgun shots, or any other heavy-hitting guns to deal with it. If he spawns from the Bottom Left or Bottom Right, then you must hurry. Try to get to him ASAP, and use a Speed Coil to go faster. Once you are there, immediately use a Sniper or Railgun to take a chunk of his HP. Always aim for the head with a Sniper that isn't the Railgun.

If he blows up the Core and it is above 5000 HP, immediately repair it with upgrades, regardless of your Coin Amount. It will cost you tons in the future because many NPCs can also do tons of Damage, and will chip away at your Core.