A small fungus (cap 1-5 cm),  with pinkish to brownish scales on the cap and a smooth stem with fragile ring. The free, crowded gills are white or cream, darkening with age.  It usually has a pungent, rubbery, unpleasant smell.

There are similar dapperlings, but most do not have the unpleasant smell

smell

Photograph from top down and in side view, showing ring, and you must note the smell and habitat.

Grows on the ground near to trees, and often in woodland.

July to October.

Widespread and fairly frequent in Britain.

Fairly frequent in Leicestershire and Rutland.

https://www.first-nature.com/fungi/lepiota-cristata.php