Well, the OED gives several possibilities. If one is 'frogging', one is 'catching frogs, fishing for frogs'. One might 'frog' a coat - that is, apply 'frogs' ('An attachment to the waist-belt in which a sword or bayonet or hatchet may be carried.' or 'An ornamental fastening for the front of a military coat or cloak, consisting of a spindle-shaped button, covered with silk or other material, which passes through a loop on the opposite side of the garment.'). And so on.