Peter, un chaton sauve de la noyade, est adopte par une famille de citadins. Mais Peter n'est pas un chaton comme les autres car face a ses semblables, il prend la defense des souris, des rats et des herissons.

Fem små kattunger ble født i en låve langt ute på landsbygda, hvorav den ene manglet en hale. Barna Olle og Birgitta tigget og tigget om å beholde den lille krabaten og til slutt foreldrene hadde med seg. Og slik begynte Pelle Svansløs sitt nye spennende liv i storbyen.

Peter-No-Tail is a cat who's born without a proper tail on a farm by the Swedish countryside. Due to economical difficulties, the farmer is forced to get rid of Peter. The farmer can't bring himself to drown the cat, so he sneaks Peter inside the car of a family who are renting a house close to the farm for their summer vacation. When the family finally reach their home in Uppsala, Sweden, they find Peter and decide to keep him. Without a tail, he becomes the talk of the town among the other cats and, especially Mike, who teases him cruelly. Mean Mike and his two companions, Bill and Bull, are notorious for the nasty tricks they like to play on other cats. Mike is currently trying to court Molly Silk-Nose, but his rough and silly approach does not impress her, since she becomes interested in the kind and gentle Peter. But Mike won't give up that easily and he has a plan for how he'll get his revenge.

I en ladugård långt ute på landet föddes en gång fem små kattungar, varav en saknade svans. Barnen Olle och Birgitta tiggde och bad om att få behålla den lilla krabaten och till sist gav föräldrana med sig. Och så började Pelle Svanslös nya spännande liv i den stora staden.

Il gattino di campagna Peter, nato senza la coda, viene adottato da una famiglia che vive ad Uppsala. La sua anomalia fisica viene presa di mira dagli altri gatti, in particolar modo dal perfido Måns che gli dà il tormento. Quest'ultimo inoltre corteggia la bella Maja Gräddnos, che però rifiuta i suoi modi antipatici preferendogli la dolcezza di Pelle.