The mother in Anthony Browne's new picture book is not only "a good fairy" but "as beautiful as a butterfly and as comfy as an armchair... as soft as a kitten and as tough as a rhino". He says it's all true, but he made up the mother's flower-sprinkled dressing gown that envelopes every page in the companion book to My Dad. To celebrate Mother's Day this Sunday, we want you or your pupils to find your own similes and metaphors to tell us why mothers are special in one short sentence starting "My Mum is ..." Anthony Browne will illustrate the best idea in a one-off black and white artwork, and the winner will also get a signed copy of My Mum, which is published by Doubleday at pound;10.99. Send your entry plus your name, address and a contact number by email or post to the address on the right, quoting My Mum offer. The first four names out of the hat on March 10 will win.