who created them?
The idea came from Jay Kogen and Wallace Wolodarsky.
Kang and Kodos
 The idea of Kang and Kodos came from Jay Kogen and Wallace Wolodarsky, writers of "Hungry are the Damned"
what is kang and kodos? They are a duo of fictional recurring characters in the animated television series "The Simpsons"
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Kang and Kodos [SEP] Creation
Kang and Kodos first appeared in the second season in "Treehouse of Horror". The idea of Kang and Kodos came from Jay Kogen and Wallace Wolodarsky, writers of "Hungry are the Damned". In the script, Kang and Kodos were shown as "an octopus in a space helmet with a trail of goo". The finished design was based on "EC Comics" cover issue. Although originally designed to constantly drool, Matt Groening suggested that they not drool all the time to make the animation process easier. However, the animators did not mind the work, leading to the drooling staying in the script.