That's not a real baby, that's just Three dressed up like 1.

That's not a real baby, that's just Ziggy dressed up like 1.
Stingy says this to Sportacus, Stephanie, Trixie and Pixel.

That's not a real baby, that's just Cookie Monster dressed up like 1.
Bert says this to Ernie, Big Bird, Telly, Baby Bear, Elmo, Grover and Herry.

That's not a real baby, that's just Mr. Tanaka dressed up like 1.
Knuckles the Echidna says this to Sonic the Hedgehog, Miles "Tails" Prower the 2 Tailed Fox, Amy Rose, Cream the Rabbit, Shadow the Hedgehog and Cosmo the Seedrian.