The most significant feature of the Furby was the fact that it also sounded like a surprised rabbit that had just been trodden on.
Furbys (that's the official plural - not Furbies) could "speak" and (apparently) learn. When first powered on they would speak a nonsense language called Furbish and over time gradually switch to speaking proper English. They could also communicate amongst themselves.
Because of the way that Furbys "learned" to speak English, many people believed that they were actually repeating what they had heard. This led to some amusing news stories as organisations such as the National Security Agency gave instructions that Furbys were banned from their premises in case they repeated sensitive information. The reality is that not even the most ruthless interrogator could have prised state secrets from a Furby - they didn't really "learn" but had a built in vocabulary of some 160 words.
Furbys took the toy world by storm and some 27 million were sold during one 12 month period alone - eventually over 40 million were sold worldwide. To some of those who lived through those dark days it resembled the classic Star Trek episode The Trouble With Tribbles. It seemed that everywhere you turned one of these cute, fluffy robots was chattering away - and they didn't even have an "Off" switch! Thank goodness they didn't have the ability to walk as well as talk or I for one would have committed mass furbicide.
Various other Furby models were available to buy over the years such as the Furby Babies range introduced in 1999. As if that wasn't bad enough there were also a number of Furby variants based on characters such as Gizmo and Yoda.
It also has a more advanced voice recognition system and can speak hundreds of words.
I reckon it would make a nice snack for a Roboraptor...