Dash and Dot are robots from Wonder Workshop. They come together in one of the kits. Dash is the bigger one that can move around, and dot is the smaller one that is basically just a head with some sensors, no moving parts. My daughter wanted dash to enable dot to move around, so I designed this simple trailer that allows them to travel together.

You will need some super glue and 2 skateboard bearings. Everything was designed to be printed without supports.

Dash and Dot connectors are based of https://www.thingiverse.com/thing:3321647, but the rest is completely designed in tinkercad.