Fel Orc Kodo Beast

Fel Orc Kodo Beasts appear in the Blood Elf campaign, while Chaos Kodo Beasts are used in the campaign after Grommash Hellscream drinks from the Chaos Well. They both have a different skin color compared to normal kodo.

Trivia

 * The only difference between the Fel Kodo and the Chaos Kodo with regards to their statistics is their defense type and gold cost.
 * Chaos Kodos have heavy armor and cost 300 gold.
 * Chaos Kodos are counted as an idle peon, which means that on that particular map their unit type is probably worker.

Speculation
The Fel Orc Kodo Beasts serving the Fel Horde in Outland might have been clefthooves instead.