Bast is canon, and the most commonly worshipped Whiskerling deity.

There is an additional pantheon in this adventure, but these deities are specifically mostly worshipped by Rattikin

Gnibblis, the Tidekeeper
Domain: Trickery, Nature
Symbol: A coiled rat's tail encircling a drop of water
Gnibblis is a cunning and adaptable deity revered as the master of tides, both literal and metaphorical. They embody the ever-shifting balance between survival and risk, urging their followers to embrace change and use wit and resourcefulness to overcome challenges. Gnibblis’s teachings often come in the form of parables about clever creatures outwitting stronger foes.
Note: Gnibblis is the most commonly and openly worshipped Rattikin deity in this region

Churnroot, the Bogfather
Domain: Nature, Death
Symbol: A gnarled root twisting around a skeletal paw
Churnroot is a grim yet benevolent figure who governs the cycles of life and decay in the swamp. To the Rattikin, Churnroot represents the inevitability of death, but also the richness of rebirth as the swamp consumes and renews. Offerings to Churnroot often include scraps of food or decayed matter, symbolizing gratitude for the bounty of the mire. His shrines are simple, adorned with twisted roots and small pools of stagnant water.

Squeeva, the Many-Eyed
Domain: Knowledge, Trickery
Symbol: A circular cluster of beady, overlapping eyes
Squeeva is a goddess of cunning and vigilance, often depicted as a massive, many-eyed rat lurking in the shadows. She teaches her followers to value knowledge, to watch and wait, and to strike only when the odds are in their favor. The Rattikin believe that Squeeva’s countless eyes see all that happens in the GlimmerMire, and they often pray to her for guidance, luck, and protection. Her altars are small and hidden, usually decorated with tiny bones, shells, or glittering objects meant to catch her many gazes.

Scuttleshade, the Maw Below
Domain: Trickery, Tempest
Symbol: A jagged crescent, like the outline of an open submerged maw
Scuttleshade is a chaotic and somewhat fearsome god, revered for both their ferocity and their role as protector of the downtrodden. Legends say Scuttleshade once ruled the swamps as a massive, predatory beast, but they grant their power to the smallest and meekest creatures to even the odds. The Rattikin see Scuttleshade as a defender of their kind, offering prayers to keep the swamp’s larger predators at bay.