The Iron Guardian Stirs – Archenemy scheme. You know, it's not really all that evil to have a golem standing by in case you're attacked. In a way, most Archenemy players are being ganged up on unfairly! That's "players who are playing the Archenemy," not "anybody playing Archenemy," if you see what we mean.
Guma – Urza's Saga uncommon. You can see from the art and flavor text that the Guma likes to hunt at the edge of the water. This makes sense for a creature with protection from blue, since it has nothing to fear from even the toothiest shark.
Assault Zeppelid – Dissension common. In their natural form, Zeppelids are blue-aligned creatures. But the Simic mages have grafted green magic into this one to make it more warlike. You can see the pure blue version on Stratozeppelid.
Mesa Chicken – Unglued common. The art for Mesa Chicken represents Kev Walker's interpretation of the instruction to create a real, yet majestic, chicken.
Devout Harpist – Urza's Legacy common. We can't improve on this comment by tavaritz: This was the 200th Magic card which name started with D if we count the Urza's Legacy cards in alphabetical order. If in collector's number order then it's Defense Grid.
Grizzly Bears – Seventh Edition common. After illustrations by Jeff A. Menges and Una Fricker, Grizzly Bears got an illustration by D. J. Cleland-Hura, which is the art it stuck with for the rest of its stay in the core set. That stay ended in Tenth Edition, since Runeclaw Bear took its place starting in Magic 2010.