Not a lion with a gazelle but what I think must be a Scorpion Fly and an ex-hoverfly of some description. The tail end certainly looks scorpion-like though I don't think it is a sting. In one of the pictures you can see the long head which the Collins insect book says is typical of these flies. Does anyone know the species? - there is nothing in the book with a greenish body. I have other photos which show the wings more clearly.