When enchanted creature dies, mill cards equal to its power
Unlike the Giant Shark, which tends to inhabit trade binders and junk rare bins, the Shambleshark may strike at any place, any time
I am not sure what the other threats to pair with Malcom in such a deck would be, but it is an interesting area to explore
A 2/3 just isn't big enough to have a meaningful impact on most Commander games, even with the upside of potentially growing in power if an opponent's graveyard is full
It determines: Your life total, which sets the initial margin for how much damage you can sustain
Other good three-color options include the evergreen Muldrotha, the Gravetide, and Saruman of Many Colors who gets a bit of extra value from having guaranteed access to a high-cost spell in the companion zone