Scientist
The scientist is the healer of the zombies it places a machine that shoots purple goo and heals zombies so they can get back into action. The scientist has a warp that allows him to teleport in front of him to get close to enemies or get away so he can re-heal the scientist has a bomb called the sticky explody ball that sticks to things can then blows up. The scientist stays behind the all stars and foot soldiers as they kill the plants the scientist heals them. And the engineer makes teleporters and turrets so he can help the zombies get close to the area they need.