Out of the sea
465 million years ago
Some animals ventured onto land as far back as 500 million years ago, but they only visited briefly – perhaps to lay eggs in a place without predators. Plants were the first to take up permanent residence on land. The first land plants were relatives of green algae, but they rapidly diversified.
See other: History of Life
Knowledge Guild 
You’re an amphibian of some type, I suppose. You’re getting royally fucked on the regular by other animals there in the deep, or shallows, or wherever you happen to be in the water. Eventually you and your fam decide to leave all that behind, at least briefly, a few times a year, and go somewhere crazy. “Land.” Unfortunately this desperate ploy isn’t enough and inevitably it’s water, not “land,” that becomes the exception.
I suppose the point is that they’re not colonizing or colonizers. The first land creatures are fleeing and refugees.