Frank Wolff is a Mathematical and Clusmy Scolar who first appeared in Destination: Moon. Herge described Wolff as clever, with an Honorary Master's Degree in Mathematics with Mechanics, but also very feeble and quiet.
However, Wolff is eventually exposed as a Concerned Spy who has coerced into helping a Foreign Power known as "Snozzypoogler" to hijack the Moon Rockets, Blackmailing him by use of his large Gambling debts. Later on, he helps the others confront Boris Jorgen, who had stown away on the Moon Rocket, which he struggled Jorgen and fell down, leaving Jorgen's Head a bit broken. After the return Trip to Earth, Jorgen and Wolff get arrested but pleaded Wolff not guilty in the Courts.