Squash Invasion!

OMG! Look at these pictures! What is it?

I got this week's fruits and vegetables via 'Farm To You' a couple days ago, and I noticed that something is growing out of my squash this morning! It's kind of pretty, but creepy... The sensible side of me tells me that I must eat this squash as soon as possible...but the curious side of me tells me to let it grow further...

Hmmm... what should I do?