Maybe. Will your morphed image look enough like either one of the original mascots, or maybe both of them, so that the teams' consumers could be confused and buy products wtih your mascot on them instead of theirs?
The use of someone's IP might also subject you to a claim of "dilution." In other words, you're blurring the rightsholder's IP by creating this new version that riffs off it in a way that makes the original less distinctive, special and recognizable.
Since you haven't even created this hybrid animal yet, no one can advise you as to whether it's an infringement of an existing rightsholder's IP. You're going to have to see an IP lawyer once your done and let them review the original mascots you're borrowing from and the final product.
Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.
As usual, my colleagues here have spoken well. There is nothing new under the sun. Every logo, ever new word, every brand is based on bits and pieces of other associations that are out there in the world. The only thing that matters in trademark law is whether there would be a likelihood of confusion between your new logo and either of the ones you are basing it on -- or, as Pamela Koslyn aptly points out, whether you risk "diluting" either of them either.
These are basically questions only experienced trademark lawyers can answer with any degree of confidence -- which is not to say they are guaranteed to give the "correct" answer, only their best professional advice.
And, after all, you asked "could I be sued," not "should you be sued." Unfortunately, big companies (such as sports franchises) often push their true trademark rights further than a court would recognize, realizing that most defendants cannot afford to get an ultimate ruling from the courts. So you could be sued even if you ought not be sued, and an experienced trademark lawyer will be able to help you understand the risks of that happening.
There's a flip side to this too: You may very possibly not be sued even if your new logo is indeed so close to the legal line, or even over it, that suing would be fair and reasonable. Most high school logos don't come to the attention of the NHL! Again: Your lawyer will help you understand how to factor all this into your actions.
Instead of taking the intellectual property of other sports teams (who are often on the look-out for unauthorized uses of thier logos), and risk being sued for infringement, you may want to look at a microstock or micropayment subscription site that provides royalty-free licenses to use photographs, vector images, and clip art for specific permitted uses. The license essential gives you legal permission under the copyright to use the clip art for limited uses (such as for advertisements, posters, or flyers). This may also include modifying and combining several images into a new image. Payment terms and permissible uses under the licenses will vary from site to site. These sites often provide you with an opportunity to review the license before downloading.