David Tennant is Basically Lex Luthor’s Assistant
While the real life David Tennant does not appear to be associated with super villains in any way (though we always keep our eyes peeled just in case), comic writer Paul Cornell based an Action Comics character on him.
The character of Spalding, Lex Luthor’s Assistant, was created by Cornell to resemble David Tennant. Paul Cornell also wrote for Doctor Who, so the connection is not surprising.