Each School Crossing in Nottingham NG3 & Gedling NG4 has little plaster guardians. Here’s the very first one that I pictured on the OSM map (placed 3 April 2016, it is on a traffic choker on Gordon Road, outside of the Bluebell Hill Primary School:—

…and here is the latest one, which is on Foxhill Road East, placed on the Zebra Crossing outside of the Carlton Central Infant & Nursery School (school was turning out as I took this picture last Monday, as you tell by all the cars parked close to the zebra):—

[a personal note: I find it rather surprising that neither the choker nor the zebra crossing (nor cushions or, presumably, all the other paraphernalia of street furniture) appears on the map; it doesn’t seem to be much point in adding it all, then]

I assume that these little figures are there to remind motorists of the young lads & lasses that may stream out from the school gates. However, I have zero idea what the local council call them, and am even not fully certain that the council are responsible for them.

Added later:
One issue in the “missing street furniture” is that it is not possible even to search on Zebra Crossings, etc.. They are utterly missing from the map.

SK53 has called these plaster children “School Sentinels”, which I like a lot. Here are the other ones photographed 31 May outside Hogarth Academy on Porchester Road: