The Exceptions

Weird Evolutions
Some Pokemon evolve in ways too complicated to fit in a small area on the Pokemon sheet. Those are listed here:

Slowpoke (and Shellder)
Slowpoke and Shellder evolve by combining one of each. Additionally, to form a Slowking the Pokemon must have a symbol of kingship, such as a King's Rock.

Eevee
Hoo boy. Eevee evolves into Flareon, Jolteon, and Vaporeon through exposure to fire, electric, and water energy respectively. It evolves by friendship into Espeon if its trainer prefers the day or Umbreon if night, so it can spend more time getting closer to its trainer. If exposed to aggressive moss it will evolve into Leafeon while bitter enough cold will cause it to evolve into Glaceon. Finally, it gets a tick mark on its evolution track every time it participates in a Pokemon theater play and every time it wins an award. At the end of every play, you can roll a d6 to check for evolution. Rolling less than or equal to the number of ticks causes it to evolve into Sylveon.

Eevee evolves into Nucleon, a fan-made Pokémon, if exposed to intense nuclear radiation.

Tyrogue
Tyrogue evolves based on its EV's. If its strength is higher, it becomes Hitmonlee. If speed, Hitmonchan. And if they're even, Hitmontop.

Wurmple
Wurmple evolves into Silcoon by the assist method. It evolves into Cascoon by the battle method.

Nincada
Nincada splits into Ninjask and Shedinja.