If this code is the one you are loading, then you need a shim in the configuration you pass to RequireJS because taffy is not AMD-aware. I believe this should work:
shim: {
taffy: {
exports: "TAFFY"
}
}
I've never used taffy so I'm not aware what its dependencies might be. You might need to add a deps: [...]
field to the shim so that the dependencies are loaded ahead.