 The first consumer model was introduced on 11 May 1999.New models were released every year until 2006.Although most models were dogs, other inspirations included lion-cubs or huskies/jack-russel terrier/bull terrier, and space explorer, and only the ERS-7 version, ERS-110/111 and ERS-1000 versions was explicitly a "robotic dog", but the 210 can also be considered a dog due to its jack-russel terrier appearance and cute puppy face.