Heaps of left over yarns that won’t make even a sock, a bit of time on your hands, and some toddlers who like to “cook”?
I found that turning old yarns into crochet play food is very convenient: you can throw them in the washing machine when they have been chewed by snotty kids, they do now get broken/ break anything when they are thrown, and in my opinion they look nicer than the tacky plastic stuff.
Also, I enjoy creating things but at the same time I am lazy (well, short of time for big projects), so making these is perfect perfect for me: I get the sense of fulfillment when they get fast ready, I get to give my children something they like, and I get to relax when doing them while watching telly or sitting on a bus. I have not used any patterns, I just make them up as I crochet, but I am sure there are loads of patterns for similar (and fancier 😉 ) stuff online.
For me this has been a free and fun hobby, that allows me to use my imagination and creativity, to use up old stuff that would otherwise be thrown away, does not take up much space nor energy, can be picked up anytime, and gives me an opportunity to make something for my kids that they like.