The first stage of Flood, the spore infects anything edible, then uses the prey's body for it's own benefit.

 

Carrier Stage

 

The final or second stage, is a big boulbous Flood that releases spores after it suicidely explodes.

 

Human Stage

 

One of the second stages, is an infected marine that will either melee attack or use a weapon.

 

Covenant Stage

 

One of the second stages, is an infected elite that will either melle attack or use a weapon.