Gagh

Klingons enjoy eating living worms called Gagh.

Klingon word

There are two different words to describe these worms: ghargh is the word for "serpent worms as animals", while the word qagh refers to the worms served as food "alive, but with seasonings and sauce added"(1).

Serpent worm

During an interview, Marc Okrand said that the authors of Star Trek: The Next Generation had made a small mistake when overseeing a small comma in TKD: The entry for ghargh says "serpent, worm" (2), but some authors read this as "serpent worm".

It was only in the addendum where Okrand introduced the new definition "serpent worm" with the new word qagh.

Why two words

Many actors mispronounced ghargh with a /g/ - i.e. /gakh/ or even /gag/ (rhyming with frog), Okrand adapted to this pronunciation and added it to the new edition of the dictionary.

References

1 : StarTrekKlingon

2 : The Klingon Dictionary p. 86