Tiamat's Fanatics

You choose whether each token is attacking the player or a planeswalker they control as the token is created. If it's attacking a planeswalker, you choose which one.

Although the tokens enter the battlefield attacking, they were never declared as attackers. Abilities that trigger whenever a creature attacks won't trigger, including the myriad ability of the tokens. If there are any costs to have a creature attack, those costs won't apply to the tokens.

The tokens all enter the battlefield at the same time.