Yes, serpent is a synonym for snake, absolutely (...dragon also means snake). But I presume serpents in Magic are typically not snakes, as those are separate types (which have never occurred on the same card!), and the art typically portrays them as a mix of fish and snake characteristics.

Serpents are sea monsters in Magic. The question that came up with Serpents was we felt a lot of people would say yes “serpents” are an Earth animal as it’s a synonym for snake.

I’m curious from a design perspective regarding characters that do and don’t get cards in sets, specifically using Koma as an example.Story-wise, we know that the Kaldheim serpent was phyrexianized through flavor text in MoM. Obviously not every character can be represented in the set, but as with such a prominent character on its plane, what ultimately led to their exclusion from the set and supplemental content such as the commander decks? Was Koma originally in MoM but then later cut? Or was there simply not a place for it given it’s potential colors and rarity? Again, I’m mainly curious regarding the choice to exclude a card/character that is referenced within the set, and simply using Koma as the example talking point.

The flavor text was written after the set was finalized. That might have been the first time it was known that Kona got Phyrexianixed.