Fantastic Beasts: 21 WTF Moments
8. Occamy Grows/Shrinks To Fill Size... Sometimes
There's an excellent sequence in the middle section of the film that sees Newt and his new allies attempting to capture an enormous Occamy, which has grown to fill the attic of the house it is nesting in. The rule here is that the creature - classified as a choranaptyxic - will always grow to fill whatever vessel it is housed in. That results in a great scene in which the wizards trap it in a teapot.
But all spectacle aside, the film ignores its own rule AGAIN when it clearly shows several Occamy inside the enchanted suitcase. Surely they should be kept in individual cages to stop them growing? Not just left in their nest. Or that might be a consideration if the science of choranaptyxicity weren't completely avoidable when the plot doesn't need it.
Like when the Occamy is born inside the bank and doesn't grow to fill the bank, for instance.