The only thing that i dont like is that the render is so high res while the background is full of noise

I would definitely add some noise to the Incy Wincy Spider Good work and good luck!

Funny creature, but some tiny points: light source from the background come from up left behind, I'd expect something similar for the spider. The background image has quite some depth of field, if you move the spider more behind and make it smaller, it fits better with the background (or pick another background with few depth of field). In the flor I see some reflection from the objects, the spider should have some reflection too. Good luck!

Mighty cute. Great idea well done