A lamb was blinded in a "wicked act" of torture by two boys believed to be about 12 or 13 years old, police have said.
North Wales Police said it had been left "truly appalled" by the "torturing, hurting and ultimately blinding a defenceless animal".
It happened in the Waterloo Port area of Caernarfon, on 9 February and police are trying to trace the boys involved.
Police said the lamb's back was broken and it may have to be put down.
Officers have urged seven girls who were seen watching and laughing to come forward and urged people to do the "right thing".
Sad Update: The lamb may have to be euthanized due to a broken back caused by the kids.— Tîm Troseddau Cefn Gwlad HGC/ NWP Rural Crime Team (@NWPRuralCrime) February 19, 2020
We still need the publics help to catch the offenders.
I still cant believe that people who may know is responsible are staying quiet...do the right thing and contact us https://t.co/ABBc4pK0ZS
The force's rural crime team tweeted: "Sadly we deal with cruelty on a daily basis as part of our job but to realise children could do something so awful shocks us."
In a video posted on Twitter, PC Dewi Evans said the lamb also suffered a back injury after the boys were seen "throwing the lamb to one another" and "trying to throw it into a stream".
In a second video posted on social media, Rob Taylor who manages the rural crime team, made a direct appeal to the children involved.
He said: "Our appeal is to those children - don't have sleepless nights, have a chat with your parents and discuss the right thing to do."