I was wondering if there is an official monster in 5th edition that has resistance against any combination of bludgeoning, piercing or slashing damage and an immunity against any combination of bludgeoning, piercing or slashing damage dealt with non-magical weapons on top of that.
While I was looking through various monster stat-blocks I noticed that resistance to bludgeoning, piercing and slashing damage is extremely rare (e.g. Treant) and it bothered me that a Rakshasa for example has almost no physical durability because when the players get to fight one, it’s likely they already have magical weapons.
I’m thinking about homebrewing a monster that has resistance to the common damage types and an immunity to the common damage types if the attacks are made with nonmagical weapons, but I wanted to know if that already exists in 5th edition because I like to stick with official material instead of inventing something totally new.