[Sundae]

I've not (yet) been caught out with a mean nickname.
But I have often instigated new names for people I work with.

For example I once worked with a lady called Leisha.
She had a cloud of frizzy red hair.
Many year before, there was a programme on TV about a redhead called Marmalade Atkins, so I secretly called her Marmaleisha. Which worked really well. And it progressed into The Lady Marmaleisha (as per Lady Marmalade).

It suited her so well that eventually too many people knew, and she became aware of it. She didn't like it an awful lot, but I don't recall it was ever traced to me. And it suited her anyway.