Term used for video game sequels that are completely unrelated to the first one. Some infamous examples include Super Mario Bros 2, Zelda 2: The Adventure of Link, and Castlevania 2: Dracula's Curse. Games like these have different gameplay mechanics and sometimes completely different enemies and final bosses (Except for Castlevania 2 in this case).
For all 3 games mentioned, they have elements that are carried on to later games of their series.
Person A: Remember that game Super Mario Bros 2?
Person B: Yeah that game was a bastard child of the Super Mario series. Bowser wasn't even in the game.
A clown bastard child is a child who was possibly switched out at birth by entities unknown (clown bastard aliens)...possibly as a joke on the unsuspecting parents. Parents may leave the hospital with what they perceive to be the most sweetest child in the world...only to discover about 5 years later that the child's behavior is so atrocious it makes the parent proclaim that the child could not possibly be theirs because of how said child acts. The parents were fooled because the child resembles them but his actions later in life may prove otherwise. These children are often spawned...not born
broken down-
Clown- because it seems a joke was played on you.
Bastard- because this child surely CANNOT be yours!