Funny story. I asked that myself recently and was given this answer.
"No one knew what to name it, then someone mentioned the old bugs bunny cartoons and quoted some lines...
that's all it took"
I looked up the cartoon , and found this was the lines mentioned.
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Hugo the Abominable Snowman: [holding Daffy, whose shirt makes him look like a rabbit] Oh, what a cute little pink bunny rabbit!
[cradling Daffy]
Hugo the Abominable Snowman: Just what I always wanted. My own little bunny rabbit. I will name him George, and I will hug him and pet him and squeeze him...
Daffy Duck: I'm not a bunny rabbit...
Hugo the Abominable Snowman: ...and pat him and pet him and...
Daffy Duck: You're hurting me. Put me down, please.
Hugo the Abominable Snowman: ...and rub him and caress him and...
Daffy Duck: [shouts] I ain't no bunny rabbit!