The latest addition to the Parker garden railway fleet is this Playmobil diesel from the 4024 freight train set where it's accompanied by a tank wagon and flat wagon.
Based on the standard LGB-derived motor block, it's an incredibly smooth runner. Despite being turned into a toy, the design looks really good too. Replace the handrails, refine the window surrounds and add some dirt, it could pass for a far more scale model.
I wondered if there was a resource listing all the Playmobil trains, and it turns out there is.
Walts Playmobil Collection lists the full range along with photos. I know I should want more scale, but the PW machine with a grab on the back, would be rather nice...