You can always just sacrifice this black creature, so the nontoken wording is mostly going to stop your opponent from sacrificing a random token
These are typically green cards since green is the MTG color most associated with the power of nature, mana abundance, and lands
Best White Metalcraft Cards #7
The more I write about Elspeth, the more I realize this is just one of the strongest planeswalkers, niches be damned
The second problem is that you need to draw multiple creatures before you can use these spells to their full effect
For most decks, being restricted to only cards that cost three or more means that Keruga, the Macrosage has the same exact issue as Gyruda, Doom of Depths: you only get to play a single card over the first three turns of the game, leaving you in a position where you're often dead to aggressive decks (this gets even worse in older formats, which are faster and place a higher value on efficiency)