In the video games, a Shiny Pokmon is distinguished by a color variation compared to its normal version, and the probability of encountering a Shiny Pokmon is extremely low, making them particularly rare and special
Thantis the Warweaver, Basandra, Battle Seraph, and Fumiko, the Lowblood perform similar feats, only at a larger scale
Drawing a second card each turn gives Morska two +1/+1 counters, and the best part is that you can trigger this on your opponent's turn as well, giving you lots of opportunities to draw tons of cards and have an unstoppable commander
Worst-case, you have a grizzly bear, and best case you have a two mana 2/2 that draws you a card -- which is just a great deal