Because someone saw the need for a hellgrammite and a sweet young lass should have wander'd close and said the most immortal words of this modern era, "cor, that's a woolly bugger, eh wot?"
Except she weren't English, but in fact she was of the english... So one might surmise the words may have been something along the lines of "gosh, that's a woolly bugger, ya dumb bunny."
Except, you know, the english thing, not being Dutch, or Deutsch if you prefer.
So she probably just said, "that's a woolly bugger, dad."
The rest is history.