Gorochu
Gorochu was intended to be an evolution to Raichu in Generation 1. However, for a number of reasons it did not make it to the final cut. It is considered a Beta Pokemon since it was never truly finished. With the information I could find on the Internet and the help of @JOEtheDM's Poke5E Monster Manual and PHB, I was able to patch together what a potential stat block for this Pokemon would look like along with some lore.
God of Thunder
“Its name was Gorochu. It had fangs and horns and looked like a god of thunder.” That’s how Atsuko Nishida first revealed an evolved form of Raichu had been cut from the first generation of Pokemon games... “Chu” is the squeak sound a mouse makes in Japanese... “Goro” is the sound of thunder. -Lava Cut Content
Evolution
Gorochu evolves from Raichu starting at level 12 and above only during a thunderstorm. When it evolves, its health increases by double its level, and it gains 12 points to add to its ability scores.
Gorochu
- Type: Electric
- Classification: Medium | SR 13
- Minimum Level Found: 10
- Egg Group: Field, Fairy
- Gender Ration: 50% M / 50% F
- Evolution Stage: Beta
- The Mouse Pokemon. It may be cute, but it can
- store unbelievable amounts of electricity.
- Armor Class 16
- Hit Points 120 | Hit Dice: d12
- Speed 40ft. walking
STR DEX CON INT WIS CHA 14 (+1) 20 (+5) 17 (+3) 6 (-2) 14 (+2) 10 (+0)
- Proficient Skills: Acrobatics, Intimidation
- Saving Throws: Dexterity
- Vulnerabilities: Ground
- Resistances: Electric, Flying, Steel
Static: When this Pokemon is hit by a melee attack, roll a d4. On a result of 4, the attacker takes an amount of electric damage equal to this Pokemon's proficiency bonus.