Animal archetypes modify familiars’ standard abilities, similar to how class archetypes modify player characters’ class features. These archetypes function by swapping out certain abilities that are common to standard familiars and replacing them with new abilities tailored to a particular theme. Where levels are referenced in archetype descriptions, they refer to the class level of the PC master in whichever class grants the familiar as a class feature.
Shapechanging Familiars: Familiars that can take various forms, such as the magical child’s animal guide, imps, and quasits, must have the same archetype for each form, and it must be legal for all of those forms (meaning if any form is an improved familiar, it can’t take archetypes that don’t stack with improved familiar).
Improved Familiars Restriction: The abilities of an improved familiar don’t stack with those of any familiar archetype that alters or replaces the variable bonus a familiar grants its master or speak with animals of its kind. (A leshy warden’s leshy familiar doesn’t grant a variable bonus or speak with animals of its kind, so it doesn’t have abilities that stack with those familiar archetypes.)
Note: Familiar archetypes modify familiars’ standard abilities, similar to how class archetypes modify player characters’ class features. These archetypes function by swapping out certain abilities that are standard to common familiars for new abilities tailored to particular themes. Unless otherwise stated, levels referenced in this section refer to the familiar’s effective level, which is the master’s combined levels in the classes that grant that familiar.
A decoy misdirects its master’s enemies, allowing the master to strike by surprise.
Class Skills: A decoy treats Bluff as a class skill.
Deceitful A decoy gains Deceitful as a bonus feat. This replaces alertness.
Mockingbird (Ex) At 5th level, a decoy can speak any of its master’s languages. At 7th level, it can mimic its master’s voice and intonation perfectly.
This ability replaces speak with master and speak with animals of its kind.
Master’s Guise (Sp) At 11th level, a decoy can transform into a perfect likeness of its master, as the alter self spell. It can hold this form for up to 1 minute per caster level; upon changing back, the decoy must remain in its natural form for an equal amount of time before transforming again.
This ability replaces spell resistance.
This feat allows you to acquire a powerful familiar, but only when you could normally acquire a new familiar.
Prerequisites: Ability to acquire a new familiar, compatible alignment, sufficiently high level (see below).
Benefit: When choosing a familiar, the creatures listed here are also available to you. You may choose a familiar with an alignment up to one step away on each alignment axis (lawful through chaotic, good through evil).
Improved familiars otherwise use the rules for regular familiars, with two exceptions: if the creature’s type is something other than animal, its type does not change; and improved familiars do not gain the ability to speak with other creatures of their kind (although many of them already have the ability to communicate).
Under improved familiar restrictions it says that the leshy warden's familiar stacks because it has no speak with animal or variable bonus which I believe is the +2 to a specific skill. Since most improved familiars that I skimmed through can neither speak nor do they give a skill bonus wouldn't they be capable of stacking?