Mr. Krabs' Doll-a-Rama is a collection of dolls owned by Mr. Krabs that only appears in the episode "Wet Painters."
It is a baby blue rotating display that consists of several baby dolls.
Role in episode
After SpongeBob and Patrick get permanent paint on Mr. Krabs' First Dollar, they are scared for their lives and do their best to remove it or hide the evidence, which doesn't work. Mr. Krabs later comes home from the grocery store and thinks the pair "have a dirty little secret." He takes a look around and thanks them for their hard work, however, he then overreacts upon witnessing that they messed up his Doll-a-Rama by misplacing one of the dolls, so he places the said doll back in its correct position, resulting in it saying "mama" when Mr. Krabs touches it.
The way that Mr. Krabs reacts by taking a pause in between the second syllable in "Doll-a-Rama" makes SpongeBob and Patrick anxious, believing that he found out what happened to his first dollar, which he didn't.
Its name may be a reference to the Dollarama store franchise.