Venom has been widely studied in vertebrates and some invertebrates, but venom research in crustaceans is relatively underdeveloped due to its rarity. A novel origin of venomous systems in crustaceans is not only fascinating in an evolutionary context, but also opens the door to discovering new molecules and proteins that have serious applications in the biomedical field. Caprellidae, commonly known as the skeleton shrimp, have been observed using putative venom to fight other males, yet little is known about the biochemical composition and evolutionary significance. To gain insight, we have conducted a transcriptomic analysis of the caprellid’s putative venom glands, using RNA sequencing and bioinformatics tools (Trinity, TransDecoder, and toxin databases) to identify secretory and potentially toxic proteins. We have also conducted functional bioassays to test the damage and lethality of putative venom on caprellids. By collecting secretions from the gnathopods of adult male caprellids and injecting it into healthy adult male caprellids, we were able to compare the rate of mortality to a controlled population. We hypothesize that Caprella mutica produces venom for male-to-male competition, making it one of the few known crustaceans to have evolved venom for the use of intrasexual competition. This research provides insight into venom evolution in crustaceans and aims to uncover novel bioactive compounds with pharmaceutical potential.