"The Dream of a Thousand Cats" was originally published in The Sandman issue #18 (1990). "Calliope" was originally published in The Sandman issue #17 (1990).
One of Madoc's novels is called 'Eagle Stones,' a minor plot point in Neil Gaiman's 'American Gods.'
The Crow/Skull Bird is voiced by Neil Gaiman, the creator of the graphic novels the series is based on.
David Tennant and Michael Sheen lend their voices in Dream Of A Thousand Cats. They also star in "Good Omens", another of Neil Gaiman's TV adaptations.
James Mcavoy, Michael Sheen and David Tennant were also in the audiobook adaptation of "The Sandman".