(To the tune of “Boggis, Bunce, and Bean”)
DS9 s2e19 “Blood Oath” featuring returning TOS actors William Campbell (Koloth, s2e15 “The Trouble with Tribbles,” also played Trelane), Michael Ansara (Kang, s3e7 “Day of the Dove”), and John Colicos (Kor, s1e26 “Errand of Mercy”)
IIRC, there’s a line at the end of those episodes about the Klingons doctor working on restoring appearances. Guess they were at the back of the queue