I found it in a toy market in Beijing a few years back. Chinese toy market are always brilliant. Have been to hundreds. Toy markets are getting rarer now, as most folks buy toys online, but in smaller cities there are still plenty.
The smaller robots in turn trans into construction trucks, a process called Trans Truck Engineering.
Each of the small robots has a kinky ready-for-the-trans-club name. This in Titan. Yeah, Titan the mighty excavator! He/She looks properly dangerous.
The dump truck is called Fire King. Totally trans. I asked my kids if they wanted to have the set; it was only 60 yuan, but they were more interested in a Joop Rubicon:
Much smaller as a toy compared to the Super · Trans, but what do I know..? So I got the Joop and left the Trans Truck to engineer it out themselves.