Tigerism has for a long time been on the increase among writers; for since it has been the fashion in the great world to take up any scribbler who has libelled, fought, or eccentrized himself into notice, the spoiled child of the season has found it easier to outrer the dress and deportment of a gentleman for the occasion, than to assume it: in other words, the public make lions of these men; and they, by a slight transformation, make themselves tigers.
Source: wiktionary