ChangelingChangeling is a characteristic-defining ability. “Changeling” means “This object is every creature type.” This ability works everywhere, even outside the game. See rule 604.3. (CR 702.73) (This card is every creature type.)
When this creature enters,
createTo create one or more tokens with certain characteristics, put the specified number of tokens with the specified characteristics onto the battlefield.
If a replacement effect applies to a token being created, that effect applies before considering any continuous effects that will modify the characteristics of that token. If a replacement effect applies to a token entering the battlefield, that effect applies after considering any continuous effects that will modify the characteristics of that token.
Previously, an effect that created tokens instructed a player to “put [those tokens] onto the battlefield.” Cards that were printed with that text have received errata in the Oracle card reference so they now “create” those tokens. (CR 701.7) a tapped Mutavault token. (It's a land with "
: Add
" and "
: This token becomes a 2/2 creature with all creature types until end of turn. It's still a land.")