fantastical
adj.describing something that is very strange, imaginative, or not real. You use this to talk about stories with magic or things that are hard to believe.
adj.characterised by the use of imagination to create things that are not real or are impossible. Often used to describe literature, art, or situations that involve fantasy elements.
“The children built a fantastical castle out of cardboard boxes.”
“The author's fantastical descriptions of the underwater city made the story feel like a dream.”
“While the plot is fantastical, the underlying themes of social justice and environmental degradation are deeply rooted in our current reality.”
“Other claims by Arday seem to be fantastical, including the fact that he apparently ran 30 marathons in 35 days.”
“The University of Cambridge professor, now resigned , was accused of plagiarism, and appears to have made up an awful lot of fantastical stories about his life.”
From fantastic + -al.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.