"Collabs" are big in the retail caricature world, where I earn my daily bread. They happen when 2 caricature artists sit down to the same easel with the same subject and create a drawing together. If you trawl the feeds of current caricature greats like @komakes and @ninjasketch you will find some awesome examples of such collaborations.
I've brought these fun exercises to my illustration studio practice and my fave collaborators are my kiddos and youngest students. While it's super stimulating to draw alongside an accomplished artist there's something pure and exciting about working with another person who is completely untrained and makes marks on instinct. There's a reason why Picasso was obsessed with kids' drawings. They are totally dope! Here are a few collabs that I've done with my own kids. I encourage you to draw with the kids in your life too. It's a great way to pass the time together and share your passion for scratching on paper. Check out image captions for some tips.
*Here my kids asked, "how do we draw trees?". I scratched out this little scene, inspired by our day of sledding in upstate New York. My son drew his own tree (which is maybe sporting an owl on top?) then we digressed into how a stuck-out tongue is put together. This is all very high level stuff ;)
*Another fun option is creating a space in the drawing specifically for their input. I've always had an inexplicable compulsion to fill word bubbles with non sequitur imagery. This was just a continuation on that theme! Oh, and we got into some material play, experimenting with putting a light value colored pencil over a darker value ink.
*In this one I encouraged my kids to commit graffiti- perhaps the eldest of all the mark-making arts. Do try this at home.