Let's not forget that the Romans occupied much of Britain two millennia ago. True they may not have been able to scale a 3' high wall to get into Scotland but they where pretty much everywhere else in Europe and Africa. could they have introduced the lion as a symbol? We also had King Richard the Lion-Hearted. As for dragons not existing, of interesting note they do show up in different cultures that had no connection with each other. And lastly might I remind you that there was a Stewart that saw a 6' rabbit that no one else saw!