The Magic: the Gathering (MTG) set Onslaught (ONS) was released on Oct 7th, 2002. It includes 4 token cards.
Onslaught is an expansion set in the Onslaught block. An expansion set in Magic: The Gathering is a pool of cards released together and designed for play in the same environment. Standard cards and tokens in a set can be obtained at random through booster packs. Sometimes a set will contain promo tokens that are given away as prizes at Friday Night Magic (FNM) or special pre-release events.