Spider Climb. The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check. Keen Hearing and Smell. The weasel has advantage on Wisdom (Perception) checks that rely on hearing or smell.
Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 7 (1d8 + 3) piercing damage, and the target must make a DC 11 Constitution saving throw, taking 9 (2d8) poison damage on a failed save, or half as much damage on a successful one. If the poison damage reduces the target to 0 hit points, the target is stable but poisoned for 1 hour, even after regaining hit points, and is paralyzed while poisoned in this way.
Another experiment of the Transmutation expert Lorwyn Gorwick. A mixture of a Giant Spider and a Giant Weasel. The Giant Speasel has the body and head of a giant weasel, but the legs of a Giant Spider