Fillin, short for Fillin the Blank, is the pseudonym used by Rottytops in order to sneak into the Half-Genie Festival on Paradise Island in order to spend time with Shantae.
"Fillin" is a bit forgetful and awkward, as a result of Rotty not thinking through her cover story as a half-genie. She occasionally teases others in a lighthearted way.
One of the "Half-Genies" that is performing at the Half-Genie Festival, she ends up abducted by an unknown assailant, forcing Shantae to rescue her. After Harmony tells Shantae that Fillin is not really a Half-Genie, Shantae realizes who she truly was before going off to rescue her. She is rescued in the Squid Pit after Shantae manages to power it on in time and gives Shantae the Jet Octo Fusion Coin after reverting back to Rottytops.
Trivia
Her disguise is given away by the following:
According to the NPCs on Paradise Island, all Half-Genies are a hybrid of human fathers and genie mothers. No other hybrid between a genie and another species other than human has been shown in the series so far.
She gives Shantae and Harmony different answers when asked about her name.
Rottytops has been known to enjoy cosplay.
Her outfit takes care to hide her stitched arms and legs, which would quickly give her away if shown.
Because Rottytops is a zombie, Fillin does not have pointed ears from Half-Genies.
