Xenagos, the Reveler

[+1]: Add X mana in any combination of {R} and/or {G}, where X is the number of creatures you control.
[0]: Create a 2/2 red and green Satyr creature token with haste.
[−6]: Exile the top seven cards of your library. You may put any number of creature and/or land cards from among them onto the battlefield.

Pioneer Masters

Commander Legends: Battle for Baldur's Gate

+1: Add X mana in any combination of {R} and/or {G}, where X is the number of creatures you control.
0: Create a 2/2 red and green Satyr creature token with haste.
−6: Exile the top seven cards of your library. You may put any number of creature and/or land cards from among them onto the battlefield.

Theros

+1: Add X mana in any combination of {R} and/or {G} to your mana pool, where X is the number of creatures you control.
0: Put a 2/2 red and green Satyr creature token with haste onto the battlefield.
-6: Exile the top seven cards of your library. You may put any number of creature and/or land cards from among them onto the battlefield.

Creature cards with bestow put onto the battlefield with the third ability will be creatures on the battlefield, not Auras.

Xenagos's first ability isn't a mana ability. It uses the stack and can be responded to. Count the number of creatures you control as the ability resolves to determine how much mana to add. You choose how much of that mana is red and how much is green at that time.