Parallax - Season 1 Episode 1 One Big Happy Family
Overview: On an otherwise ordinary day in the coastal town of Werrinup, Ben discovers in quick succession that there is a portal to a parallel universe in an old drain, he has a sister, his mother is a Guardian of the Parallax, his best friend has a sneak thief double from another world and these large flying purple insect things (Welkin) want to bite him.