They have information that you can't easily see from your hand, especially if you don't want to tip off your opponent that you have it
The titan is the progenitor of the eldrazi that leave everything in their wake in geometric destruction with their reality-warping powers, and Kozileks own cards often involve drawing cards in some way
The turn you play her, you will probably want to use that ability so you dont immediately kill her by using the -3 ability
The fact that you can use it offensively and defnesively while still having most of your other resources free is a pretty big deal
Steeped with romantic nostalgia for pre-scientific ages, theres just something about a sea serpent that makes us, like Agent Mulder, want to believe
Explorers of the Deep The Ixalan merfolk deck has a legendary reputation for crushing other precons