Here's the most common version of the lyrics:
Le Chat Noir
Le chat noir, le chat noir,
Est dans le jardin,
Il fait miaou, il fait miaou,
Il est très malin.
Il saute, il court,
Il se cache, il dort,
Il attrape les souris,
C'est un vrai bandit.
Translation:
The black cat, the black cat,
Is in the garden,
He meows, he meows,
He's very clever.
He jumps, he runs,
He hides, he sleeps,
He catches mice,
He's a real bandit.
This song is a classic in French children's music. It's often sung with actions, like miming the cat's movements.
Let me know if you'd like to hear the song sung! I can provide a link to a YouTube video or audio recording.