Arcane/Steam Punk-esq creatures

[DMThac0]

Background:
I have a BBEG who is creating machines powered by arcane energies. In an attempt to show the world that their co-existence with the arcane is archaic, he is trying to usher in this new era of technology. He has fashioned the machines to be his army as he is going to invade the country that he felt he was exiled from.

Problem: I'm not sure how to create these types of creatures as I have never really homebrewed any unique creatures before, simply re-skinned. I would like to create minotaurs, beasts, giants, warforged and more.

Could you fine folks help me get a start on this? With some help I'm hoping to come up with a template I can share when the brainstorming is done.

[Bearon]

Which system is this for?
D&D 3.5? 5e? Other?

[DMThac0]

It's for 5e.

I'm currently looking into the Iron Golem as a base line for the creatures, I figure they're the closest creatures in the MM to what I'm thinking so far.

[Stan]

One way to go is to create a simple template then assume that the creator makes everything based off an existing monster. Apply the template to a few monsters and you're done. You can also look at animated objects, shield guardian, and helmed horror for ideas.

Off the top of my head:
condition immunities: charmed, frightened, poisoned

damage immunities: necrotic, poison, possibly psychic.

damage resistance: this could vary, but maybe nonmagical slashing

AC+2 due to being totally metal

Str+2, Con+2, Dex -2, maybe set values for int, wis and char, such as 8,8,5, respectively.

CR+1 is a guess, but it will vary by initial CR and creature.

For comparison, Pathfinder has several templates, (http://www.d20pfsrd.com/bestiary/monster-listings/templates) including construct and clockwork.