Question about mob's energy levels

Just a quick question about something I've been wondering about.
Do most monsters have energy in the sense that human players do? For example it seems that the stone summit in slaver's all have either very high energy, or no cap at all. A normal normal monk can't just spam spells and expect to have any energy, but it seems that most monsters can spam their spells as long as they are alive.
Any one have an answer to this?

They have higher amounts of Energy Regen than players do. Which allows them to spam skills a lot more.

PvE monsters do have a limit to how much energy they have. It is fairly similar to a real player. This has been observed using skills like Famine or Mind Wreck which deal damage when the enemy hits zero energy.

The reason monsters can spam spells ad noseum is because they have a very high rate of energy regen. Like, a perminant +6 or higher regen.

I mean, to be fair, this is one of the only ways (besides having a higher level and health) to make monsters in PvE challenging. If they ran out of energy mid-fight, PvE would be pretty dang easily since AI tends to spam high energy stuff.

Thanks for speedy responses, just been wondering about this for a while. Can now close thread.