What is this weird cable?

Someones robot is missing a grounding cable:

https://www.revrobotics.com/rev-31-1269/

Hmmm... actually, it appears to be the same photo. I'm guessing yours was taken off a screen?

The yellow connector is an xt30/xt60, and this obviously ties ground on it to some sort of ground screw.

Beyond that it could be from anything. Those connectors are common, but frequently used on drones and other rc gear.

That is an XT__ connector for a lithium battery. They are commonly used for radio controlled toys like cars, planes, and drones. The single terminal connection is odd and is likely made for an unconventional special purpose.

These connectors are required for much higher current flow and voltages that multi cell lithium batteries are capable of producing.

There are many clones of the connector shown below and these do not have the same text as pictured. As far as I know, most clones are XT-60.

Earthing cable? No idea what it plugs into

A path for electrical current to flow through

It could be what the other commenter said, but it could also be some kind of coaxial thing like for an old TV. I've seen cables with the circular loop end that would go on the part where the cable would go, and you need a nut to secure it. The other end, though, looks like a molex power connector, which is the only reason I think it could be some kind of grounding thing.

It's not a great angle though; I can't see well enough up the yellow part's inside to see what the prongs look like.

Rc car cable the orange end fits a common rc car battery

Looks like a custom made cable judging by a lug connecting to an unknown connector via heatshrink. Will need a clearer picture of the yellow connector to work out a possible use.

It looks like the cable setup i had to install in my car when i got the tow hitch installed. Plug on the left goes to the trailers' brake lights, and looks like only a grounding bit on the other end.

Is it something made to test fuses/ reverse current devices. Screw red end into ground, then plug yellow into love and hopefully everything works as intended otherwise fire extinguisher time?

Plugs into my cock!