"SRL had a GUINEA PIG robot. It was kind of a four legged waldo that the guinea pig rode on top of. It is described in detail (with photos) in Re/Search publications PRANKS.
IIRC the critter’s feet where strapped in and is motions were used to control the motion of the four legged bot he was riding. So if the pig walked forward, the ‘bot walked forward, if it ran back, the ‘bot ran back. Mark Pauline claims that they fed the critter lettuce the whole time and it enjoyed it very much."
I have / had a copy of Pranks.