My husband has worked with a few lads with strange nicknames: -
One lad was known as "Sandbag" because he always wore a long sheepskin coat the same colour as a sandbag.
Another lad was known as "Posh" because he was the scruffiest kid ever (dirty clothes, dirty hands & dirty house, apparently)
Any my favourite is "Hozzle". This came about because, when he wasn't at work, he was sleeping in bed, always horizontal - shortened to 'Ozzle.