I'd like to put in a request for a phylactery guard. A slightly old idea:
Falen, the lich in question, is a Defiler druid. Her phylactery is stored in a forbidance warded pocket demiplane (she had help!). The plane is inside a bottle, any visitors get shrunk to a minute size. It's in a cave at the opposite end of the plane from the entrance. To get there, you have to cross devastated plains and forest.
I want to place a guardian out there. My initial thought was a very small undead vermin - not shrunk to fit the plane. From inside the bottle the thing would be an absolute monster.
I looked at making it an extremely large zombie or skeleton - but it just came across as a little boring, and most likely very easy to defeat... so I'd be interested in something that looks like this, but poses more of a challenge... Hopefully being able to deal with flyers or PCs deciding to hang back and attack from range.
Any normal sized bug or small animal would do. For some reason, either a mouse or cockroach appealed.
Ideally it would weigh in at CR 13.
If you've got time for this one it'd be really cool!