During World War II, Felix was the proposed name for a German/Spanish seizure of Gibraltar. It was scheduled for 10 January, 1941 but never executed. This plan was discussed at a meeting held between Franco and Hitler in late October, 1940, in Hitler's railroad car at Hendaye.

Franco's material demands for joining the Axis powers included:

• 400,000-700,000 tons of grain
• All the fuel required for the Spanish Army
• All lacking equipment for the Spanish Army
• Artillery, airplanes, and special troops for the conquest of Gibraltar

In addition, Franco wanted Germany to hand over the territories of Morocco and Oran, and to "help [Spain] get a border revision in the west of Rio de Oro".

Hitler later said he would rather have three teeth extracted than to meet with Franco again.

It is subject to historical debate if Franco overplayed his hand demanding too much from Hitler for Spanish entry into the war, or if he deliberately stymied the German dictator by setting the price unrealistically high.