The RSPCA is looking into complaints from the public after a man claimed he had harmed and killed cats and could sell people traps to help them do the same.
The man took to social media to say he had allegedly killed 23 cats in Swansea and used a range of methods such as poison, traps, bricks and a vehicle to run them over.
He described it as "great fun".
The man also boasted he had 200 "awesome cat killers" for sale which work by snapping cats' legs before they are left to die.
He also claimed he was "hoping" to get hold of a poison 100 times stronger than rat poison, but said it "won't be as exciting" as the "awesome" trap.
In another social media comment, he described how he allegedly ran three cats over on Monday in Gorseinon. According to the comment, two died and one crawled away with a "snapped back".
He claimed he targeted all cats that entered his garden, though none of the claims have been confirmed as true.
How to report animal cruelty
A spokesman for RSPCA Cymru said: “We can confirm we have received calls in regards to this.
"We are so grateful to people who report suspected animal suffering to us and we would like to reassure people we will always look into and, if necessary, investigate any complaints made to us about animal welfare.
"RSPCA Cymru is hugely concerned about any alleged animal suffering and would urge anyone with any information to contact us on 0300 1234 999."
A spokeswoman for South Wales Police said: “We can confirm this has been reported to us and we are in discussions with the RSPCA.”
