Yeah “meeces” is a made up plural form of mouse. Pixie and Dixie from that cartoon @FreedomFlower pointed out are the meeces.
And I found this about Mr Jinks the cat on the Hanna Barbera wiki:
Mr. Jinks is a character in The Huckleberry Hound Show. He is the cat who constantly chases Pixie and Dixie, of whom he routinely said, “I hate meeces to pieces!”
‘Aint your average Huckleberry hound’ - Atomic Dog
Lyrical side note re : she’s a mermaid (Rita) / Rita the Mermaid.
When the album first came out and My Brother and I went over all the characters in the songs and on the cover art, Rita the Mermaid hit like , Ok there’s not a lot of Ritas out there- but it flows. Recently however it hit me - is it possible George was doing one of his Beatles song Name checks with a flip?
Was Rita the METER MAID Of the Beatles lexicon flipped into the P Funk world with George’s usual word play? Especially how Mr Wiggles Pronounces it .
George references the Beatles here and there - Even A Day in the Life gets a nod in Knee Deep on the Guitar Solo.
George loves them Beatles. Sure, who doesn’t. He’s acknowledged their influence and there’s a few nods and artful theft here, there and everywhere 
He also says he loves Cream. I don’t. I’m glad I can’t see any Clapton references. Can’t stand em 
I’m glad Eddie covers She’s So Heavy on his solo album. My favourite Beatles cover.
much later
Oh…sunshine of your love… Balls!
Oh well I never liked that anyways. 