Donald and the Loch Ness Monster: An Adventure in Scotland is an illustrated text story. It features Scrooge McDuck and Donald Duck, as well as the first appearances of Ian McDuck and Hugh McDuck. The Loch Ness Monster is also mentioned.
Scrooge and Donald, visiting Scrooge's cousins Hugh and Ian in Scotland, hear tales of the Loch Ness Monster, which frighten Donald. but it is Donald himself who does the frightening after he becomes entangled in weeds and driftwood and is mistaken by the Monster by the Loch sightseers....
Behind the scenes
Donald and the Loch Ness Monster: An Adventure in Scotland was published as book #20 of the Disney Small World Library series in 1990 (or 1991, according to some sources).