Outlast {W} ({W}, {T}: Put a +1/+1 counter on this creature. Outlast only as a sorcery.)
Each creature you control with a +1/+1 counter on it has flying.
Several creatures with outlast also grant an ability to creatures you control with +1/+1 counters on them, including themselves. These counters could come from an outlast ability, but any +1/+1 counter on the creature will count.
The cost to activate a creature's outlast ability includes the tap symbol ({T}). A creature's outlast ability can't be activated unless that creature has been under your control continuously since the beginning of your turn.