Siamese Twins

Siamese Twins is a Crossword variant in which two identical grids are presented at the same time, with their clues merged into the same list.

Background
The name 'Siamese Twins' comes from the colloquial name for conjoined twins, wherein two twins are born with some degree of fusion between their bodies, often sharing a body part. The puzzle does not share this level of connection, however, instead have a 'conjoined' set of clues, despite have distinctly different fills.

Puzzle Application
Siamese Twin puzzles distinguish themselves by containing two or more identical grids (often traditional American blocked), and a unique form of clue list. Rather than listing each grid's clues next to each grid (or separately at all), every clue for a particular number/direction is listed under the same number in the same list. As a result, an average Siamese Twins clue list would begin with two distinct clues for 1A.

While it doesn't usually matter which grid someone assigns their first answers to (assuming the grids are in fact identical), but some puzzles will pick thematic first entries and pre-place them in the grids to give solvers a place to start.

Sometimes, a Siamese Twin puzzle will avoid crosswords entirely, instead applying the concept of 'two puzzles whose clues have been lumped together' to other genres, like logic puzzles.

Played Straight

 * - While the grids themselves are somewhat odd (being very long compared to their height), they both solve like normal crosswords. What's done with them afterwards is a different story entirely...
 * - The logical conclusion to the question of 'how many puzzles can be included in one Siamese Twins puzzle?' Evidently, the answer is five (although nobody has attempted more than that as of yet).

Notable Twists

 * - What appears to just be a pair of diagramless Siamese Twins may surprise solvers as they complete their fills. Each puzzle contains four black cells that contain letters in the other grid, shaking the expectation that the 'twins' must be identical.
 * - Rather than listing both clues for a given entry under the same number, this puzzle mashes them together into one nonsensical string that needs to be unraveled in order to solve either of the clues.