The girls turn into senior citizens when they drink a potion meant to make them older.
Bubbles is seen in her original 1998 counterpart's design in the flashback of what happened to Pokey Oaks Kindergarten. Kristen Li (the voice of Bubbles in the 2016 series) voices '98 Bubbles, rather than Tara Strong reprising her '98 counterpart.—yamilethgu-70417