Matthew Hayden, the imposing Australian opener, was nicknamed 'Big Fish' along with other nicknames like 'Haydos' and 'Unit' - all referencing his large physical build and powerful presence at the crease. Hayden was known for his aggressive batting and was one of the most destructive openers in cricket history. 'Shark', 'Volcano', and 'Burger' are not recognized nicknames for Hayden.