Pathfinder 2e monster making help

[LaRayna]

Hey guys, I'm kind of reaching out for help because I'm having a hard time getting the basics of monster making. Specifically, how many and what kinds of abilities should monsters get depending on their creature level.

[farothel]

If I have to do stuff like this, I have three tactics I often use:
-take a monster that already exists and just swap around a few abilities. For instance, you want a creature at home in the snow and you have a fire creature you like, swap immunites, vulnerabilities and weaknesses from fire to snow and vice-versa, give it maybe a small extra bonus for sneaking while in snow and you're done for the number crunching.
-look at a few creatures of the level you want and see what they have. That works best for things like attack, perception, saves and HP as they tend to be in a certain range
-For humanoid adversaries, look at your player's abilities. We for instance have a rule at our table that whatever the PCs can do, NPCs can also have (mostly for games like Vampire or Scion and the like, but it still works for PF as well).

[LaRayna]

If I have to do stuff like this, I have three tactics I often use:
-take a monster that already exists and just swap around a few abilities. For instance, you want a creature at home in the snow and you have a fire creature you like, swap immunites, vulnerabilities and weaknesses from fire to snow and vice-versa, give it maybe a small extra bonus for sneaking while in snow and you're done for the number crunching.
-look at a few creatures of the level you want and see what they have. That works best for things like attack, perception, saves and HP as they tend to be in a certain range
-For humanoid adversaries, look at your player's abilities. We for instance have a rule at our table that whatever the PCs can do, NPCs can also have (mostly for games like Vampire or Scion and the like, but it still works for PF as well).

Thanks for the advice. That's a little helpful.

My players were interested in a Castlevania themed campaign so there are a few monsters I'll have to make from scratch.