Does anyone know if you need to do something specific to make the frankenpie after you have all the pieces in your inventory? I have them all but nothings happening and I feel like I'm missing something really obvious!

It's been 300,000 years since I've made one, but if I'm remembering correctly, you have to click on one of the pieces (while all 8 are in your inventory) and click the 'combine pieces' option (it may be phrased slightly differently)

How in the world did I miss that...I was staring RIGHT AT IT when I clicked on it! AHHH I feel so silly, thank you so so much!

No problem; enjoy your new minion! ^_^