The development of Groot — code-named Project Kiwi — is the latest example. He is a prototype for a small-scale, free-roaming robotic actor that can take on the role of any similarly sized Disney character. In other words, Disney does not want a one-off. It wants a technology platform for a new class of animatronics.

Cameras and sensors will give these robots the ability to make on-the-fly choices about what to do and say. Custom software allows animators and engineers to design behaviors (happy, sad, sneaky) and convey emotion.

“And all of this technology must disappear, which takes a crazy amount of engineering,” Ms. Evans said. “We don’t want anyone thinking, ‘That’s the most sophisticated robot I have ever encountered.’ It has to be: ‘Look! It’s Groot!’”

Project Kiwi will next advance to the “play test” stage — a short, low-profile dry run at a theme park to gather guest feedback. Disney declined to say when or where.