The Silver Death's-Heads are the gang members that appear in the Doc Savage adventure Death in Silver. They are identifiable by the costumes they wear: silver suits that cover them from head to toe, with facial markings that creates an eerie appearance of death. The suits are made from coin silver by the gang themselves.
The gang uses identical expensive watches set to a specific time as a substitute for a password.
The mastermind of the gang is unknown, but Bedford Burgess Gardner is considered to be the most likely suspect.
Ull is the leader's chief lieutenant and main scientific mind. Ull develops a number of gadgets including an acid-based contact poison used in an attempt to kill Doc Savage.