They stuffed a kitten into a jar and posted pictures of it - prompting angry netizens to complain to the Society For The Prevention Of Cruelty To Animals (SPCA).
The photos, taken by two males in Malaysia, went viral last week.
One Facebook user called Ai Knowl has admitted to the cruel act and has apologised for doing it.
"It was meant as a joke," he said.
His post got 251 likes, reported Malaysian news portal The Daily Chilli.
Ai Knowl, who lives in Johor Baru, assured netizens that the cat is alive.
"Tomorrow I will post some pict and vid that cat are still alive.. Dun worry..(sic)" he wrote.
The other person has yet to admit to the deed. But netizens are not buying Ai Knowl's story that the kitten is still alive.
One netizen, Mohamad Azuan, said Ai Knowl should be kept in a bottle instead.