The F.B.I. (for Famously Bonkers Individuals) was a secret spying organization.
This "F.B.I." was founded by malevolent Toons who had infiltrated human society for some nefarious purpose in the late 1990's. To defuse investigations about them, they took the bold approach of substituting themselves with the real government organizations who should have been handling the matter, and hire investigators to unmask their own plot. Only, the investigators they picked were the phenomenally oblivious Donald and Daisy Duck, who utterly failed to unmask any of the disguised Toons.