I think the evidence is flimsy for the use of lions for executions in Britain. This image of a lion on an elaborate key is interesting, nevertheless:   https://www.miragenews.com/thrown-to-lions-new-evidence-from-roman-britain-609741/ https://www.kcl.ac.uk/news/thrown-to-the-lions-new-evidence-from-roman-britain-executions-revealed