Those of you with a santa (and espetially a reindeer) do pictures for 50p or £1 of child with santa and or deer. BUT don't charge for under 1 year olds.
Have a volunteer either with an instant camera or with a lap top and printer so the photo is instant.
My dad was santa for a few years at the local church and my mum did the photos, the babies tended to come back the next year.
What about bulbs and seeds as gifts? Santa could challenge them to grow something.
Magic spring onions / everlastnig spring onion - enviromentally friendly.
Buy a bunch of spring onions, chop off the onion about 2 cm from the root and use in some cooking.
The child gets the root, pluss a jar (jam jar is fine) and you could add some of those bead things you use in flower aranging, they absorb a load of water.
The child takes the onion home, waters it and it grows a new onion. It might be worth doing a few beforehand so the child can see what they get in a week or two. You don't need a garden they grow on a windowsil as long as you keep the roots wet.
If you want to be a bit healthier you could go for a 'guess the veg' cake stall.
There are loads of cake recipes with veg, I made a lovely courgette chocolate cake. You buy the cake and while eating it you get to guess the veg, get it right and you win 1/2 your money back.