>>51293037I mean, it /is/ a literal engine. Inorganic/object-mons are sort of the exception that proves the rule about wheels not being a very normal feature for animals.* See: Literally the other legendary, which is some kind of robot lizard.
*The few remaining exceptions are mons who curl their entire bodies into wheels to roll. Which is actually how pretty much all examples of rolling locomotion in real life animals also work.
I guess it could just carry around a pair of big stone wheels, like how a dung-beetle does rolling. There have been a lot of other mons with prop-objects that are physically separate from their own actual body. (Alakazam, Hypno, Cubone, Timburr, Rillaboom, etc.)