WikiRhymer has about 300 rhyming words and phrases for "maniac" starting with...

egomaniac
    nymphomaniac
      megalomaniac
        Pure Rhyme Set #1 of 1 (Add to/Edit Set Members)
        Words that have a pure rhyme on their last syllable only.
        amnesiac
          aphrodisiac
            End Rhyme Set #1 of 37 (Add to/Edit Set Members)
            payback
              playback
                way back
                  pay back
                    lay back
                      End Rhyme Set #2 of 37 (Add to/Edit Set Members)
                      shake back
                        take back
                          End Rhyme Set #3 of 37 (Add to/Edit Set Members)

                          Get Pro Features!

                          To see all the end rhymes sets, you must "Go Pro." It's only $7.00 a year!

                          I want to "Go Pro"

                          Words that "almost" rhyme on the vowel-based rhyme sound of the stressed syllable like: be/eat or maybe/shapely. (Click for more info)
                          payback
                            playback
                              way back
                                pay back
                                  lay back
                                    Near Rhyme Set #1 of 4 (Add to/Edit Set Members)
                                    shake back
                                      take back
                                        Near Rhyme Set #2 of 4 (Add to/Edit Set Members)
                                        haystack
                                          hay stack
                                            • like looking for a needle in a haystack
                                            • look for a needle in a haystack
                                            • needle in a haystack
                                            Near Rhyme Set #3 of 4 (Add to/Edit Set Members)

                                            Get Pro Features!

                                            To see all the near rhymes sets, you must "Go Pro." It's only $7.00 a year!

                                            I want to "Go Pro"

                                            Rhymes made up of more than one word. For instance, "jealous" and "tell us" or "shaky" and "make me."
                                            • grainy + black
                                            • Janie + back
                                            Mosaic Rhyme Set #1 of 1 (Add to/Edit Set Members)