Pikachu (5e Creature)
From D&D Wiki
Tiny elemental, any alignment
Lightning Rod. When a spell with lightning damage is cast against an ally within 30 feet of the pikachu, the pikachu can use its reaction to take the attack instead of the intended target. If the pikachu does this, it does not take damage, but instead has a +1 on its next attack roll.
Thunderbolt. Ranged Weapon Attack: +6 to hit, reach 60/120 ft., one target. Hit: 12 (1d12 + 6) lightning damage. If the attack hits and the target is a creature, the creature must make a DC 13 Constitution saving throw, becoming paralyzed on a failure. At the end of each of its turns, the target can repeat the Constitution saving throw, ending the paralyzed condition on a success.
Some believe that pikachu are tiny lightning elementals, which makes sense as they are constantly generating electricity no matter what they do. Even asleep they are generating this energy. To stay healthy, though, they must let this energy out on a regular basis, giving some people the idea for a pikachu generator, using these creatures to charge batteries and light buildings. Despite their small size, they are fast and powerful creatures that can run circles around they're trainers and show them why pikachu leave behind them trails of paralyzed creatures and people.