pokemon phantasmal flames booster box case Sleeved Pack Mega Lopunny ex Pokemon TCG Mega Evolution: Phantasmal

Some examples of this come in many different promo cards, like promotional Pikachus

Like the Crystal Guardians Charizard, this also has a reverse holo that fetches quite a bit of money but the regular holo can be found on TCGplayer in Near Mint condition around $100-150

The possibility of earning a Promo Pack A Series Vol

Also, some Pokemon evolve and have various forms so you can explore coloring the different versions, making sure details such as symbols and evolution chains are noticeable

It's especially good with card slingers (the acrylic ramps that drop cards through a fixed scanning position)

Doom Whisperer (Guilds of Ravnica): Not ideal if you think eight is already too many limbs