W'rkncacnter
Hero
oh wow, a whole 24 monsters, out of...3258. nice.Not just immunities, but vulnerabilities as well. The skeleton comes to mind right away, but I'm sure there are many others. Normally use your longsword but come across a skeleton version of a monster? Break out the mace.
Edit a quick search on D&D Beyond gave me 24 monsters like this.