Ghalta, Stampede Tyrant The kind of card that makes a green player giddy, its more likely that the face commander is Ghalta, Primal Hunger, since power matters. Invasion of Ikoria This might be blacklisted as a too-complicated card for the introduction to the format, but a base price of $11 might be in the sweet spot
Since Uril already has built-in hexproof and gets bigger with every aura attached, this one not only protects it but also helps it hit even harderand in the air, no less
So far in 2020, we've been averaging about one per month (and if you go back to the initial release in December, we've actually had 13 individual drops in three months, making the average closer to four drops per month since the series was announced), although the average is somewhat complicated by how you count themes that come with multiple drops, like the original Theros Gods during Worlds in February (technically, the Gods were five individual but related drops, although there is an argument for counting them as one big drop since buying all of the drops together was an option)
And yes, you can equip another mobilize creature with it to stack the triggers
Similarly, it will phase in with any counters it had on it