Hydra Agent

The Hydra Agent is a special agent that can be bought for $135 MM

It has 3 heads and each one shoots darts

Pro Version
After buying it 50 times, you unlock the pro version. The pro version shoots quicker, and it adds a ability.

Derpcules:

Derpcules cuts off a head, and 2 more appear.

Super Version
After buying it 135 times, you unlock the super version. It shoots hydra rocket pods, and the ability has 3 more heads appear instead of 2.