Spriggans Titan mauler

[Yebng]

Hey quick question, I'm building a spriggan with class levels of titan mauler barbarian, would the titanic rage's "enlarge person" stack with the spriggans supernatural ability to increase it's size?

[Paladin of Baha-who?]

Two different size increases generally do not stack.

[Yebng]

Generally I agree, and as per the spell "Multiple magical effects that increase size do not stack." These are both suppernatural abilities however and one is racially derived whereas the other is a class ability, I would compare it to casting the spell "enlarge person" on your evolutioned large/huge synth summoned eidolon, which I believe has been discussed and the consensus was it was permitted. I'm not fully sure of the difference between a supernatural ability and a spell or spell-like ability so that's why I pose the question, plus it makes for an very enjoyable monster if it's permitted

[Archaeik]

Hmmm

Supernatural Abilities (Su) wrote:

Supernatural abilities are magical attacks, defenses, and qualities. These abilities can be always active or they can require a specific action to utilize. The supernatural ability's description includes information on how it is used and its effects.

Enlarge Person wrote:

Multiple magical effects that increase size do not stack.

They don't stack to increase size category. (Titanic rage give "the benefits of enlarge person")

You should still receive the +2 str/ -2 dex adjustment as I doubt you have any other size modifier types from anything. (the spriggan adjustment is arguably racial)
The further adjustment to hit/AC probably applies per RAW... but RAW also inflicts only that -1 on a garg->colo casting, so I'd say the intent is to have the appropriate adjustment for you actual size, no more, no less.