Assuming any of them are left. That mantel is pretty long, and we KNOW Krampus has more dolls than the three we see in the close up (at bare minimum, he would have presumably kept/retrieved the Chesna one). Depending on how his standards are (if Buttercup make his hit list, he may have a pretty liberal idea of what constitutes “naughty”) and how strong he is, many of those who would be looking for them could themselves now be sitting on that shelf.

Not to mention that he appears to have both time and space traveling powers (while we know that GT does not happen in the same continuity as PPGD, it is clear that more time has passed there, since the PPG’s were long grown and dead by the time the story started, so getting child Buttercup must mean he can time travel) his pied-a-terre may be hard to get to.