Their color dictates what cards you can play, and their text sets your starting Life total (usually 4 or 5)
Every design highlights the theme, personality, and flavor of the creature or effect it represents
Some of these catch-up cards at least guarantee to give you something, like Archaeomancer's Map and Stoic Farmer, and while I much prefer this design than the all-or-nothing forms of catch-up cards, they still feel real bad if you aren't ramping with them
Well, it appears to have been caused by Bloomburrow, specifically one of the Commander precon decks released in that set: Bello, Bard of the Brambles
It comes from the 2024 Disney Lorcana Shimmering Skies set, card number 3
Fortifications can be attached to lands in much the same way as equipment can be attached to creatures