From November 1986: A MARVEL UK House Ad for the first (of 6, published 1986 to 1991) THUNDERCATS ANNUAL and the second (of seven, published 1985 to 1991) THE TRANSFORMERS (Generation 1) ANNUAL.
The Transformers edition featured all-new material. The Thundercats book reprinted the origin story (an adaptation of the "oh-look-they're-naked" pilot episode of the animated show) from the first issues of the US Star Comics run.
The Thundercats book went on sale ahead of the Marvel UK ongoing comic (which launched the following March) and the TV itself. BBC ONE aired the first episode on 2 January 1987 at 4.55pm.
The Thundercats material was subsequently reissued in another M-UK hardback: THUNDERCATS: THE ORIGIN.