Given the ease with which my pumpkins and courgettes cross-pollinate, I'd say it's a cross between a courgette and a butternut squash. Did you grow these last year? Either way, it's cute and sure to be yum ... grate it into some bread dough and bake!
Butternut squash are like this when young and then the skin hardens and goes creamer or as Ella says it might be a cross. It might not last long in colder weather.
Thanks for joining in Maggie & this is a very intriguing threesome. We get types of squash like this both in shape & colour ... the colour looks like there's been too little sunlight (hiding in the potato tops).
I'm late to the quiz, and have nothing more to offer than you've already received!