Compendium of all the "Official" Familiars

Quote from SunIsGettingRealLow96589 >>

Well, i know thats not right: from DragonHeist, Xanathars Lair, room x13:

"Albino Gazer. Xanathar dreamed this gazer into existence and sent it to spy on Thorvin, whose loyalty the beholder is beginning to question. The gazer is itself disloyal. A wizard character can befriend it with a successful DC 11 Charisma (Persuasion) check and turn it into their familiar with a find familiar ritual. When the gazer becomes a familiar, its alignment changes to match that of its new master."

In Ghosts of Saltmarsh, on firewatxh island, there is a seagull who was a wizards familiar 10 years ago, has been living on the island ever since, and a player can make them a familiar:

"RESTORING VIRGIL: Any character who can cast find familiar can attempt to restore Virgil to its former role, taking the gull as their own familiar."

Well, yes, certain published adventures have specific elements that override the general rules. That doesn't change how the general rules work.