Welsh corgis are cute, shortlegged herding dogs often kept as lapdogs. They can be trained for fairies and other Tiny humanoids to ride them as mounts.

Keen Hearing and Smell. The welsh corgi has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Most small beasts can be mounted by smaller creatures, with the correct riding equipment. Spiders require specialized equipment to ride, lest the rider fall off when the creature scales walls or ceilings. Specialized gear has its cost doubled.

Giant Jumping Spider

Small beast, unaligned

Armor Class 12 (natural armor)

12 (natural armor) Hit Points 4 (1d6 + 1)

4 (1d6 + 1) Speed 25ft., climb 25ft.

STR DEX CON INT WIS CHA 14 (+2) 7 (-2) 12 (+1) 3 (-4) 10 (+0) 6 (-2)

Skills Athletics +4

Athletics +4 Senses blindsight 10ft., darkvision 60ft.,

passive Perception 12

blindsight 10ft., darkvision 60ft., passive Perception 12 Languages ---

--- Challenge 1/4 (50 XP)

Spider Climb. The jumping spider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Lifeline. The jumping spider applies a fine thread of silk to any surfaces it climbs on. So long as the thread is intact, it is considered to be under the effect of a Feather Fall spell.

Web Walker. The jumping spider ignores movement restrictions caused by webbing.

Standing Leap. The jumping spider's long jump is up to 25 feet and its high jump is up to 15 feet, with or without a running start.

Actions

Bite. Melee Weapon Attack: +4 to hit, reach 5ft., one target. Hit 4 (1d4 + 2) piercing damage, and the target must make a DC 11 Constitution saving throw, taking 5 (2d4) 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.

The giant jumping spider is smaller than the medium sized giant wolf spider, but its compact build and strong legs make up for its lack in size. They hunt their prey by ambushing them with a powerful bound and pinpoint precision, and use webbing only for lifelines and nests.