When this Dinosaur enters the battlefield or attacks, you get to spit up a -1/-1 counter on a creature
just do something very Boros-like that rewards you for attack triggers and dealing tons of damage, because hey, you can do it again and again
It was in large part because the card held some amount of mystique, leading some people to buy in even though they didnt really have a use for it
AD: Dawn Murin 1995-2019 Wizards of the Coast LLC, a subsidiary of Hasbro.Inc
Additionally, Ayli can also spend 1 white and 1 black mana to exile a creature, which can help remove an opponents creature from the game
You can't choose to skip any visit abilities that trigger (in the Astrotorium, fun is mandatory!)