The purpose of this project is to investigate the effectiveness and safety of early antivenom administration for the treatment of red-bellied black snake bites/envenoming. Red-bellied black snakebites (RBBS) are the most common in Eastern Australia and are not routinely treated with antivenom because they appear to cause minor effects and there is concern about the risk of allergic reactions to antivenom. However, recent work by the Australian Snakebite Project investigators suggests that the early use of antivenom will reduce the chance of people developing muscle damage. This study is a randomised controlled trial of one vial of tiger snake antivenom compared to standard care (placebo) and this will provide evidence for or against the early administration of antivenom for muscle damage. The study will also investigate whether antivenom neutralises other effects of RBBS envenoming and determine the frequency of allergic reactions, including anaphylaxis, after antivenom use. In addition to the benefits for Australian snakebite treatment, the results will have global implications because there remains little evidence based on controlled trials for the effectiveness of snake antivenom in general and in particular for muscle damage.