Monster Tokens are monsters that appear on the field as the result of a card’s effect. They are not included in the Deck, and cannot be sent anywhere other than the field, such as the hand or Graveyard. When a Token is destroyed or returned to the hand or deck, they are simply removed from the field instead. You can use official Token cards or use coins, card sleeves, or any similar marker (as long as it can indicate Attack Position or Defense Position) as Monster Tokens and play them in Monster Card Zones. Each Monster Token takes up 1 of your 5 Monster Card Zones. Their battle position is always either face-up Attack Position or face-up Defense Position. Tokens cannot be used as an Xyz Material.
Judge Program Forum Rulings
These Ruling(s) have not been confirmed as applicable to the TCG.[Notes 1]
Heat Wave: Tokens Monsters Special Summoned by an effect like "Scapegoat" are treated as Normal Monsters. Therefore, "Scapegoat" can be activated during the turn in which "Heat Wave" was activated.
Kasha: The ATK of "Kasha" is determined by the number of returned monsters which are Zombie-Type while they are in the Deck. If "Zoma the Spirit" is returned to the Deck, it is not a Zombie-Type monster while in the Deck, so it is not counted. Monster Tokens are not returned to the Deck, so they will not be counted.
Swords of Concealing Light: You can activate "Swords of Concealing Light" even if the opponent controls Monster Tokens. In that case, when the effect resolves, the Monster Tokens do not change their battle positions. (For example, if a Monster Token was in Attack Position, it remains in Attack Position.) However, "Monsters your opponent controls cannot change their battle positions. Destroy this card during your 2nd Standby Phase after activation." is applied normally.
These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami. They were previously considered official and can still be correct, as long as they follow the official gameplay rules, or unless Konami has issued a ruling that says otherwise. References: 
↑Konami Judge Program Rulings are considered unverified, as their source(s) are not publicly viewable. They are not confirmed as applicable to the TCG until they have been officially published by Konami.