Our first Skull debuted in October 1940's Top Notch #9, a mastermind that framed police officer Kip Burland, causing Kip to become the Skull's arch-foe, Black Hood. Rudolph Wolk first appeared in April 1965's Sarge Steel #3, yet a later published case involved Wolk's first chronological appearance as the Smiling Skull vs World War II hero, Judomaster.
The golden age Skull was part mastermind, part fighting dynamo as he took the initiative during battles to knock out his opponent when his gadgetry failed to work properly. Often successfully.
Nazi Germany's Smiling Skull was also proficient in a form of martial arts combat, desiring to match his skill level against the best that America and (in a later appearance) ally Imperial Japan's finest warriors.
Suffice it to say, vanity led to Skull's doom when he hadobtained a brain control device from the criminal genius, the Abominable Schemer (it wasn't just the schemes, the name itself was very repugnant) and then sent him o a trap. The Schemer found his way out, and left the Skull in a virtual reality from which there was not escape. Yet was this the ultimate finality for the Skull? He seemingly perished back in the 1940's, replaced by a son in Jackpot Comics #6. Either the son adopted his father's features in the 1960's, or papa Skull escaped death's thralls. And found a neat cave HQ.
For the Smiling Skull, it was his vane attempt to obtain a duplicate of his prized silver luger from Sarge Steel and ended of bringing Steel to his secret camp. This led to Skull's downfall (in his own cave!) as his dreams of reigniting his belowed Reich were thwarted and his hostages were freed.
Two Skulls, both devious tacticians framing officers of the law (the Hood and Sarge), retaining their youthful vigor and fighting prowess from two decades after their criminal careers commenced. And both were UG-LEE!