Here are 3 cards that although not specifically tribal, that fit really well in a tribal deck, or any deck really (colours allowing)
most colors have some access, even if it is a bit temporary
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Kamigawa Champions of Kamigawa and the original Kamigawa block brought a newfound focus on legendary creatures and making legends matter, which aligns quite well with the Commander format
7 cmc is a lot for a creature that doesn't do much on its own, but with a couple other Wizards supporting it on the battlefield, you've got a mini-Cyclonic Rift every turn that will be super frustrating for your opponents to deal with, especially if you're protecting your board with Counterspells like the good Blue player you are
Removal is extremely prevalent for creatures in Commander, meaning an incidental Damnation or spiteful Swords to Plowshares can kill a Llanowar Elves or Birds of Paradise before their summoning sickness wears off, possibly setting you back before you get any mileage