Which monster do you like the most in Heroes 5 (level 4)?

Nope, this is a poll: "which monster do you like more," not "which is the best." That's why there are demonesses! ;)

What about the Royal Griffin, or the Druid? Do people like them less than, for example, the Lizard Rider?

I thought that if a monster is liked, then it's also strong and looks good.