Rainicornicopia: an Unabridged History of the Rainicorns (also abbreviated as Rainicornicopia) is an unabridged encyclopedia of Rainicorn history shown in "Paper Pete." Jake read it because he thought that he and Lady Rainicorn may one day have children so he needed the Rainicornicopia to educate his hybrid children about their mother's culture and history. However, as stated in the episode, Jake continuously read the first paragraph. "Rainicornicopia" is a portmanteau of the words "Rainicorn" and "cornucopia."
The red-bordered book has the title "Rainicornicopia: An Unabridged History of the Rainicorns." The letters on the word "Rainicorns" are written in several different colors of the rainbow, while "Unabridged History" is in yellow. The rest of the words are a bluish-purple.