are two of the most impactful cards from Reign of Jafar, bringing Amethyst/Emerald decks back into tournament top cuts
You don't have to add four copies of each card to your deck though, and sometimes it's beneficial to have fewer copies and make room for other important cards
(I know, ramping is not the best thing to do when you already have a lot of mana, but its better than nothing, and it also lowers your chances of drawing more lands.) Besides, these are artifacts, and there are plenty of ways to leverage them in other ways in the set
You can certainly play a mono-color deck
It's one thing to stop your opponent's game plan by efficiently reacting to their plays, it's another entirely to just stop them from being able to play the game in the first place
While this card has likely been power-crept out of any real play (due to the fact that any player with open mana can also create lots of their own furry, long-tailed creatures when the Liege bites it), it still stands as an important historical Squirrel-enabler, likely leading to it retaining a price above $5