Three damage to any target for one mana is too good of a deal to ignore, and most decks that can run this effect will run some number of them
The cherry on top is that the tokens have toxic, which can help you finish your opponents off before they can recover if they have a ton of life
Updated by Chris Stomberg on May 22, 2023: As mentioned above, a creature's power is hardly a great measure of just how good the card may be
You may sacrifice a creature with a mana value of 0, such as a token creature that's not a copy of another permanent, to cast a spell for its emerge cost
I proxy in expensive cards and produce them when I play
You need a card to counter abilities, like Voidslime, but then you'd also need another counter for the beefy body which is also a win con