While Barbie has seen declining sales for the majority of the year, don't count her out yet. As Cota said, Barbie is an icon, an institution.

"With any brand that has been around as long as Barbie, there are going to be some ebbs in flows from quarter to quarter, but overall she remains the No. 1 doll brand in the world and continues to deliver strong sales year over year," explained Cota. "More than just a doll, she is a franchise, a global entertainment powerhouse property, and a digital sensation well connected to millions and millions of devoted brand fans. Barbie created the fashion doll category and has been refreshing and reinventing it for many decades."

All things considered, whether Monster High cannibalizes Barbie sales matters little to the company's bottom line. Mattel's Girls portfolio features the top four bestselling doll brands in the world: Barbie, American Girl, Monster High and Disney Princess. Overall, the third quarter was the 16th consecutive quarter of growth for the portfolio.

"We work very hard, as you would expect being the leading doll company in the world, to understand what girls are doing and where white space exists," said CEO Bryan Stockton in a third-quarter conference call. "That's the objective. We look for white space and try to fill it."

"We want to grow the portfolio. Ideally, we like to have all brands grow, but there could be at any given moment some movement of sales between brands," he said.

Mattel has made a smart bet by investing in the dolls category. Dolls are one of the fastest-growing segments of the toy industry. Through the year to May, dolls grew 11% in the U.S. and 4% in Europe, according to NPD data, and as the No. 1 player in the segment, Mattel is well-positioned to reap the benefits.

"We don't believe in a "one doll fits all" approach. Rather, we aim to offer girls a broad and diverse doll portfolio that appeals to their varied interests each with unique points of differentiation," explained Cota. "Our goal is to engage girls by offering them franchises with unique reasons for being that will grow with them as they grow."

"Christmas will once again arrive on Dec. 25, and this year there will be more presents under the tree from Mattel than from any other toy company in the world," said Stockton during a conference call.

So whether or not Barbie is under the tree this Christmas, Mattel remains the one having a very, very merry Christmas.

--Written by Keris Alison Lahiff.

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