Worf
From Tardis Wiki, the free Doctor Who reference
Worf was the Klingon chief of security of the USS Enterprise in the 24th century. While on the Enterprise, the Eleventh Doctor recognised him as a Klingon, but noted that his memories were being altered. Before he saw Worf, the Doctor had never heard of them. (COMIC: Assimilation²)
He attended the Dæmon Bonjaxx's birthday in his bar on the space station Maruthea, as did the Seventh Doctor and Ace and a future incarnation of the Doctor and his companion Ria. (COMIC: Party Animals)