So last time I posted on the wrong board, so here's the question:
The core rulebook has the grab special attack under the base form, but the constrictor after advancement has special attacks being constrict. Does the constrictor snake keep its grab special attack after it advances?
It seems that it would make sense, but is it just implicit, or is there anything like an errata that clarifies this?
Yes, it keeps the grab.
The advancement sections only list the additions to the base form.
For instance, the Constrictor Snake keeps grab, low-light vision, scent, and all of its movement modes, even though none of those are listed in the advancement section.