I don't know what actual 'creature' itself made some / all of the tracks but I would hazard a strong guess that it, as Broch says, was under the command of a member of the species homo sapiens.
Re Robbi and bike skids, I feel the marks are too wide for a regular pushbike, but maybe they could be from a mountain bike with those big chunky off-road tyres?
Re JonathanD and fly tippers: there was no rubbish tipped there but a) the road has decent viz for a distance both ways (for detecting approaching vehicles), and b) where I found the marks is out of sight of nearby farms / buildings (according to how tall the 'fly-tipper' vehicles were). So swapping loads between vehicles, as you suggest, could be a possibility.
My feeling is that it could be a couple of dirt-bikes fooling around pulling wheelies and skidding the rear wheel round as they accelerate hard at an angle from the start. There are certainly several repeated patterns that would suggest that to me.
In the skid marks the longer parallel lines are not showing the remainder of the tyre tread? Why? Is the tyre not up to working pressure so the sidewalls are taking more load than designed? (It's not the only track like that on the road; there is an occasional one elsewhere on the road, within a KM or two.) The parallel lines of some of the skids don't always remain parallel in some cases. Is this where the bike / vehicle was leaning over causing uneven loading on the tyre / tyre wall?
Could it be more than one event? A 4-wheeled vehicle with uneven brakes skidding one wheel as it stopped quickly, or perhaps even by a two-wheeled trailer leaving the skid? Followed by (hours or a small number of days later) by the aforementioned dirt-bikes, or vice versa?
I'd been meaning to post the above pix (in the original post and taken early March this year) as bit of fun when I came across the following a few days ago a KM or two away, so it prompted me to do so.
I think I know what these following tracks are but seeing them caused me to go back and review the above pix to see if it was the same 'creature'. I don't believe it is. (Size 12 boot again for scale.)
I think that this is a horse doing an emergency stop. (Some riders shoe their beasties with plastic or rubber shoes rather than
ye olde ffashioned metal shoes.) The longest skid (top right in the first image) shown I feel is the right forefoot, and the termination is quite clearly horseshoe-shaped. Other regular horse-like walking gait scuffs, shaped like a horseshoe, can be seen very faintly on the road surface elsewhere nearby (not illustrated).
