Speedy

Description
The Speedy zombie is an early wave zombie only appearing on easy and normal. It first appears on wave 4 on any map. (Except Hard, Insane and Events)

This zombies doesn't really appear as a threat but unlike Normal they move much faster and groups of them could do some damage to your base.

Appearance
The Speedy zombie looks a little like the Normal zombie. The only differences are that the zombie has light blue skin and darker blue clothes.

Strategy
No strategy is really needed for Speedy zombies, but make sure your towers are fast enough to shoot them otherwise they can quickly escape your tower range and run right into your base.