| Ravingdork |
Pathfinder Roleplaying Game Superscriber; Pathfinder Starfinder Roleplaying Game Subscriber
Note that this only applies for things like the HD limitations of sleep, daze, or hypnotic pattern.
These "effective hit dice" do not grant your familiar extra feats, skill ranks, hit points, save bonuses, base attack, or anything else for that matter. Those things are determined by the base familiar stats, and your own (that is, the familiar's caster/master). The abnormal "mixed stats" is part of the arcane "bond" between the familiar and his master.