It's actually correct in english, especially in sporting contexts. Like this guy is a BEAST, or that guy is a machine, or that guy is a monster opponent. But

It's actually correct in english, especially in sporting contexts. Like this guy is a BEAST, or that guy is a machine, or that guy is a monster opponent. But that is very tone dependent, so if you say it in the wrong tone or someone interprets it differently then it can be taken badly.