The story:
When my gran was learning Welsh, one of the women in the class couldn't pronounce 'ardderchog' which is Welsh for excellent, so she'd say 'half hedgehog'. My mum relayed the story at her workplace and it stuck, and whenever anyone did a good job they'd say they got half a hedgehog.
My mum's boss was leaving and had a farewell party for the staff last night and gave them all little silver hedgehogs on chains. <3