Trackerjackers

Trackerjackers are mutts (mutations) created by the Capitol during the rebellion. They are genetically engendered wasps designed to track and kill the person(s) who disturbed their nest hence the 'Tracker' part. In their stinger they have powerful venom much more powerful than a normal wasp, most people can only stand a few stings before they die others can take more and survive.

Use in the 74th Hunger Games (may contain spoilers)
In the 74th Hunger Games Katniss found a nest (with the help of Rue) and she cut through the branch and it fell on the unsuspecting careers, both the careers and Katniss where stung. All escaped with their lives except Glimmer who was killed by the mutts.

By Hannah