Our nickname for our daughter when first born is probably unrepeatable! (Whisper: turbopooper)
Write about how the nickname came to be.
My brother and youngest sister were, for some reason, known as the "Mouldywarps". There were four of us, so we split into pairs, the two older ones - the "girls" - and the two younger ones. Mouldywarp is apparently a dialect word for mole (though I must admit I always thought the Mouldywarp was a mole CATCHER)
What's odd is that in the next generation my son was fascinated by moles. It must be something about the boys in my family... With my son it was because of the story One Snowy Night by Nick Butterworth - you'll have to read it to find out why! He has a much loved mole puppet or two and several mole china figures (Molennium...)
In E. Nesbitt's The House of Arden a contemporary boy, Edred, must be tested before he can become Lord Arden and restore the family fortunes. He meets the Mouldiwarp (a mole who appears on the family coat-of-arms).
Perhaps there are more mouldywarps around than I realised! But there isn't yet (at time of writing) a Wikipedia article about it.