He is a Kel Dor from Dorin, so he speaks both the language of the Kel Dor and the Galactic Basic Standard.
Plo Koon never had a Padawan.
Plo Koon was trained by the Wookiee Tyvokka until his dearth durin the Stark Hyperspace Confict.
21
Plo Koon's astro droid that appeared in "Shadow of Malevolence" and "R2 Come Home" is called R7-F5.
Emperor Palpatine called for the execution of order 66 and Captain Jag, the wingmate of Plo Koon, took aim and blasted Plo Koon out of the sky, when after the jedi starfighter crashed, killing Plo Koon immediatly.
Kel Dor (see more info at the related link below)
In order to unlock Plo Koon, you must complete 27 challenges (which are in Challenge Mode)
A Jedi Master
yes he did
no- Plo Koon dies in Star Wars Episode III: Revenge of the Sith over the planet of Cato Neimoidia
Captain Jag
His age has never been released