The Purby is a Furby fake similar in appearance to the Coobies, and some designs of Purby are packaged interchangeably as Poopi. It has the same electronics and sounds the same as Poopies and Kokies. They have very robotic, monotonous-sounding voices.
Purby, Poopi, and Kokie all speak some English, some Furbish, and some Japanese. Most of their English/Furbish phrases are similar to those of a real Furby. They have names like Furbys, but they all seem to have the same name, Doh-Doh. (Sometimes after sneezing they'll say "Me Doh-Doh")
They speak Japanese and Furbish.
Some known phrases:
"Ay-tay wah!" (Furbish for "feed me!" or "very hungry!")
"Ogenki desu ka" (Japanese for "How are you" or "Are you well?")
"Omoshiroi desu ne" (Japanese for "Isn't this fun?")
"Again, doo-moh" (Again, please)
"Kah dah-boh-bay" (Me scared)
"Hey, kah noh-lah!" (Hey, me dance!)
"Goodbye" (they say this if you don't play with them for a bit, and after a while they will go to sleep)
Here are two videos of a Purby in action, provided by YouTube user Furby Fan.