OK, so we hear about loads of sightings such as this one, and they usually turn out to be a dog, or something equally as ordinary.
However, on this occasion, Gloucestershire Constabulary seem to be taking the report seriously.
This investigation comes after 27-year-old Ellie Haggart was one walking her dog not far from Cotswold Water Park near Swindon last week.
She was just taking a leisurely stroll with her French Bulldog when she saw what she initially believed was another dog that wasn't on a lead.
She quickly realised that there wasn't another dog owner nearby, and that the animal she'd spotted had 'feline movement of the shoulders'.
Haggart reported the incident to the police, and they've announced that they're going to be looking into what happened, as well as appealing for information from the public.
A spokesperson for Gloucestershire Constabulary said: "We're looking into the report of a black panther sighting in the Wildmoorway Lane area of South Cerney."
They added: "Any information via 101, quoting incident 152 04-06-20."
Since the coppers shared this appeal on Twitter, there has - perhaps unsurprisingly - been a mixed reaction.
Obviously, it's quite unlikely that there is a big cat thousands of miles from home roaming rural Gloucestershire, but that does leave the question - what is it then?
If there's even a small chance that a gigantic apex predator is on the loose, shouldn't they check it out, just to be sure?
One person tweeted: "Other South Cerney residents report that they've seen one in our area in previous years."
A sceptic commented: "Funny that there is never a picture of these sightings.... in a world where we all have smartphones!"
Well, you'd have to be pretty brave to spot a panther while out walking your dog and start filming instead of running away as quickly as possible.
Another non-believer said: "I love these stories but I do have to wonder why bother investigating one sighting. Almost no chance it's real but even if it is, so what?
"If there are no reports of any domestic/farm animals being killed or threat to people, just forget about it. Waste of resources."
Let's hope that there actually isn't a panther roaming about near Swindon, right?