Toxins, both venom and poison, have great potential for pharmacological, ecological and evolutionary research. Yet despite this, many toxins, especially in marine organisms, have been relatively unstudied. This negligence within marine toxinology is surprising given the vast rise in proteomic and transcriptomic methods available to analyse toxins. This study attempts to characterise toxins of marine taxa of which little is currently known. In doing so, it provides a template for future studies to explore marine toxinology. The species chosen were lesser weever fish (Echiichthys vipera), greater weever fish (Trachinus draco) and a nemertean (Lineus longissimus). A proteomic and transcriptomic approach was taken, utilising methods as SDS-PAGE, HPLC, MS-MS and total RNA analysis to understand the composition of the toxins. Further, the morphological and ecological aspects of the toxin delivery systems were also investigated. Proteomic data obtained for both weever fish highlight key aspects of their venom composition which corroborate previous research, confirming the presence of both Trachinine and Dracotoxin along with their molecular masses. Here I have described novel venom delivery systems with unique structural and morphological features in weever fish, and have characterized three novel L. longissimus toxins, testing their effects on a natural predator. Transcriptomic analysis of E. vipera and L. longissimus toxins reveal a suite of matches to closely related toxic species indicating that gene duplication may play an important role in the evolution of marine toxins. This research has provided new insights into the evolution of marine toxins through family lineages and can potentially aid in further understanding the evolution of toxins throughout Animalia. The discoveries made in this study represent an ideal start to push marine toxinology from a neglected status and into the forefront of toxinological research.