This one's really cute and a great collector's item for your kiddo's room.
You need cardboard, toilet paper roll (or paper towel), scissors, tape and a black marker (like a sharpie). *When cutting with scissors, adults only please!
Cut your cardboard into a square shape - you want it blank!
Trace a circle (around the toilet paper roll) in the middle and cut open this hole
Cut your toilet paper roll in half (you want it short) and slot it in the middle of your cardboard hole
Tape the toilet paper roll to the back of the cardboard to secure the 'lens'
On the front side, draw your camera front (see picture)
And then let your kiddo snap away and use their imagination!