It's Tweety Bird. "Tweetie Pie" was the name of the Loony Tunes ep that Tweety and Sylvester appeared in together, for the first time. http://en.wikipedia.org/wiki/Tweetie_Pie
As something of a cartoon historian, harpua is correct. Just add to add this: In one of the first Tweety cartoons (where he's a pink, naked, featherless little bird), a couple of cats modeled after Abbot and Costello try to get him out of his nest to eat. One cat says to the other, "The bird, the bird! Give me the bird!" and the other cat, he breaks the fourth wall to talk to the audience, saying, "If only the Hayes Code would let me, I'd give him the bird all right!". Best example of GettingCrapPastTheRadar in the theatrical shorts era of cartoons.
I am a little, tiny, bird. My name is Tweety Pie I live inside my bird cage, a-hanging way up high I like to swing upon my perch and sing my little song But there's a tat that's after me and won't let me alone I taut I taw a puddy tat a creepin' up on me I did! I taw a puddy tat as plain as he could be!
I have the same poll on a predominantly UK user based board, and the results are the opposite of what they are here. You even lose at Tweety Pie polls, 'Murika.
Well... being the Merrie Melodies was a 'Murican production, I think it's safe to say the predominantly UK board is the clear loser, in this case.
What's sad is that despite it being 'Murikan, you're still wrong. There was a gentleman, Rolf Harris, who used to introduce cartoons when I was a child. He said it was Tweety, and there is no way Rolf would lie about anything.
Is it stated in the cartoons that it's "Bird", because it definitely states in the cartoons that it's "Pie"
Why do they call them 'crisps'? Of course they're crispy... let's just start naming foods by their texture.