First you'll need to get to where you're going. Jim Cosgrove is offering up a free download of his song "Gobble Across the USA" here (enter "gobble" as the checkout code). As Cosgrove notes, it's not really a Thanksgiving song, but it features a lot of gobbling and a lot of food, which seems appropriate enough for me.
[And here's a second blessing of sorts, this one coming from the Harmonica Pocket -- it's called "Give Thanks" and you can download it here.]
Moving into the main course, lots of turkey for the taking -- perhaps "Turkey Bop" from Dre Towey? (Proceeds go to the Conncecticut Food Bank, song available available here or here.)
Maybe you're not sure about turkey, considering vegetarianism? Joanie Leeds offers up "Tofurky," which contains the word "tushy," which kinda endears me to it right there:
After dinner, perhaps you'd like to work off some of those calories by walking around performing "The Gobble Song" from Spencer the Gardener. Evidently it requires walking around like a turkey. Some of them are walking like tofurkeys, I think.
Finally, a classic from Laurie Berkner. Happy Thanksgiving, y'all.
Laurie Berkner - (I'm Gonna Eat) On Thanksgiving Day (abbreviated) [YouTube]