Spiders tend to be mono-green cards and usually have reach, although the scope of spider creatures has expanded significantly with the release of Marvel's Spider-Man
The basic shell is pretty rigid, but everything around it can be changed and tuned to make the deck play the way that you want it to
With Vivi, your game plan might be a spellslinger or storm build - setting up until the perfect turn allows you to combo off
Even +1 Resist is hard to deal with and can be a real roadblock when trying to remove characters via challenging, and if a character has +2 Resist (like CinderellaStouthearted) then you can forget about it
Yes, there's people crazy enough to fill out an entire deck with Krakens, Leviathans, Octopuses, and Serpents, slapping a commander like Thassa, God of the Sea, Slinn Voda, the Rising Deep, or (my favorite!) Arixmethes, Slumbering Isle, and then smashing face with giant sea monsters
There are enough black Commanders that make incidental tokens or play in aristocrats that this card is actively going to be quite good