hellgrammite
noun
hell·gram·mite ˈhel-grə-ˌmīt 
: a carnivorous aquatic North American insect larva that is the young form of a dobsonfly (especially Corydalis cornutus) and is used for fish bait
Example Sentences
Recent Examples on the Web With rubber legs galore, a squirrel tail wing and a squishy chenille body, the bream killer looks like the love child between a hellgrammite and a tarantula. 
T. Edward Nickens, Field & Stream, 12 Mar. 2020 The lure may imitate a hellgrammite or a crawfish, or perhaps a small baitfish feeding head down. Frank Sargeant, al, 1 Sep. 2019
T. Edward Nickens, Field & Stream, 12 Mar. 2020 The lure may imitate a hellgrammite or a crawfish, or perhaps a small baitfish feeding head down. Frank Sargeant, al, 1 Sep. 2019 Word History
Etymology
origin unknown
First Known Use
1866, in the meaning defined above