Pleo DinosaurPleo History

Pleo and His Robot Relatives: Aibo, Furby and Paro

When Ugobe shipped Pleo in late 2007, the baby Camarasaurus joined a small lineage of machines built to act like living companions. Between the late 1990s and the 2000s, engineers in the United States and Japan tested very different answers to the same question: how much mechanics, sensing, and software does it take for a person to treat a machine like a pet? Looking at Pleo alongside his own timeline and three robots profiled in IEEE Spectrum's ROBOTS guide — Furby, Sony's Aibo, and AIST's Paro — shows where the green dinosaur fit in size, price, and design.

Pleo's Robot Family Tree

Companion robots of Pleo's era did not share a single blueprint. Some were mass-market toys built around one clever mechanism and sold by the tens of millions; others were high-end consumer platforms or institutional devices priced in the thousands of dollars. Invented by Caleb Chung and shipped by Ugobe of Emeryville, California, in late 2007 at US $349, Pleo occupied the middle ground: far more articulated than a toy-aisle novelty, yet priced well below luxury robotics.

Furby: The Inventor's First Hit

Pleo's closest family connection is Furby, co-invented by David Hampton and Caleb Chung and released by Tiger Electronics in the fall of 1998 at $35. As historian Allison Marsh notes in the IEEE Spectrum guide, its patent describes at length a reversible motor that drove the moving parts, including the ears, eyes, and wings, while source code written by David Hampton and Wayne Schulz ran on a variation of the 8-bit 6502 microprocessor — the chip that powered the Apple II, Commodore 64, and BBC Micro.

By some estimates, more than 40 million Furbies have been sold worldwide. The first generation ran from 1998 to 2002, followed by a Hasbro second generation from 2005 to 2007, third and fourth generations with LCD eyes and smartphone app connectivity from 2012 to 2017 at $60, and a 25th-anniversary Hasbro release in 2023 at $70 featuring five voice-activated modes, 600 phrases, an off switch, and no internet connection.

Aibo: The Robot Dog Before Him

Where Furby showed the mass-market appetite for an electronic creature, Sony's Aibo demonstrated what a high-budget consumer robot pet could do. Unveiled on 11 May 1999 at $2,500 (250,000 yen in Japan), Aibo was, in Sony's words, "quite an expressive pet, thanks to eighteen types of joints in the legs, neck, tail, and upper jaw"; the guide's spec table lists 20 motors. Its sensor suite included a CCD color camera, two microphones, an infrared sensor, an accelerometer, a temperature sensor, and touch sensors on the head, chin, back, and legs.

The first generation sold about 65,000 units, followed by second-generation models in 2001, 2002, and 2003 and third-generation releases in late 2003 and 2005. Programmable with Sony's OPEN-R software development kit, Aibo served from 1999 to 2008 in the RoboCup Four-Legged Robot Soccer League and inspired the International Aibo Convention in Tokyo starting in 1999. Sony sold more than 150,000 units before discontinuing the robot in 2006, and later announced a redesigned Aibo with advanced mechatronics in 2017.

Paro: The Robot Seal

Another branch of the family tree took animal robotics into care settings. Japan's National Institute of Advanced Industrial Science and Technology (AIST) started the Paro project in 1993 under researcher Takanori Shibata, unveiling a first-generation robot in 1998 and developing an eighth generation in 2004 before commercializing it in Japan in 2005. Introduced in Europe and the United States in 2009, Paro was certified by the US Food and Drug Administration as a "biofeedback medical device" and has been used in hospitals and care facilities in about 30 countries.

With a voice sampled from real baby harp seals, Paro is covered in white antibacterial fur with an internal heating system, seven motors, light and temperature sensors, tactile sensors on its body and whiskers, a microphone array, and a nickel-metal hydride battery rated for 1.5 hours of operation.

How Pleo Compares

Placed side by side using the figures from IEEE Spectrum's guide, the four robots show clear differences in size, hardware, and price:

Still Remembered

Each of these machines found its own audience, yet Pleo's position among them remains distinct. At 1.6 kg and $349 at launch, he shared the weight of Sony's robot dog while fitting 14 motors, a camera, two microphones, force-feedback and touch sensors, and a programmable Life OS platform into a dinosaur that cost a fraction of Aibo's $2,500 or Paro's $6,000 price. For readers exploring what made Pleo special, that middle path explains why he still holds a place of his own in robotics history.