Strider Spider (5e Creature)
From D&D Wiki
large beast, same as the rider (or really close, must have at least one in common)
Calcified Limberness. When the strider spider has advantage in attack rolls, it deals double the damage die with its Ram action.
Spider Climb. The spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Web Sense. While in contact with a web, the spider knows the exact location of any other creature in contact with the same web.
Web Walker. The spider ignores movement restrictions caused by webbing.
Web Shot. The spider shoots a stream of ensnaring webbing on a creature it can see with at least an inch of clear space between them up to 60 feet away. The creature must succeed a Dexterity saving throw or be grappled. The spider can engage in a contest of Strength with the creature when using its bonus action to reel the grappled creature towards it, moving it 5 feet. The grappled creature can make a Strength saving throw (DC10) during each of its turns, ending the condition on success.
Ram. Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: 5 (1d6 + 2) bludgeoning damage. Increases by 1d6 every two spider rider levels.
Strider spiders are meant to be fast, hard strikers. Riders select them commonly because they are much more agile than their tank counterparts. They often also have a cooler, more streamlined looking carapace design.