Female praying mantises often attack their mates during a sexual encounter, but some males attack too – and if they fail to win the fight they end up as lunch
Source:
https://www.newscientist.com/article/2265210-male-mantises-fight-females-to-mate-but-they-get-eaten-if-they-lose/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home