Mormo seems to be big among reptilian humanoids in the Scarred Lands, as nearly every one of the major reptilian races mentioned worships her. However, a lot of the major reptilian races from the core rules were left with no mention what so ever. Now that is not Sword & Sorcery's fault; the original Monster Manual was not finished when the first Scarred Lands books were released. Others were not OGL; although they did get special permission to use the Yuan-Ti. So the question is, who do those other races worship.
Let's start with kobolds. These small draconic creatures are usually worshipers of Chardun. They venerate him for his strength and pray to him for the strength to overcome their enemies. According to the kobold they were created by Chardun from the drops of blood spilled by dragons who sided with Chardun during the early days of the Divine War. They are most often found in Dunhanae where they supervise the goblin slaves that toil in that nation's mines. They also fight in Calastia's armies in the Durrover campaign. Of course none of this applies to Dragon Land kobolds.
Next up are the lizardfolk. Native to the Mourning Marsh and the Swamps of Kan Thet, lizardfolk are followers of Denev. They view themselves as defenders of the balance and protect the swamps where most of Denev's followers are at a decided disadvantage. This also places them in direct opposition with the Asaatthi that make their home in Kan Thet and place the resurection of the Serpentmother above all other concerns.
Finally we look at the troglodytes. Troglodytes are the most likely to worship Mormo of the three reptilian races presented in the core rules. However, they are more likely to worship Laathsaal, The Crawling One. Laathsaal is the only god to have actually accended and have once been mortal, which is something that troglodytes admire. He is also a savage warrior, particularly in protecting his followers from harm. Troglodytes often work with asaatthi since their god is an accended asaatthi and his desire is to restore Mormo to power. However, they just as often clash with asaatthi over territory and resources.
Well there you go, three races that are a big part of the core rules but never really made it into the Scarred Lands. Until next time, good luck and good gaming.