Deathtouch {2}{B}, {T}: Put a petrification counter on target creature. It gains defender and becomes a colorless artifact in addition to its other types. Its activated abilities can't be activated.
2012-07-01
The effects of Xathrid Gorgon's ability don't depend on the petrification counter. If that counter is removed, the creature remains a colorless artifact with defender, and so on.
2016-06-08
Activated abilities contain a colon. They're generally written "[Cost]: [Effect]." Some keywords are activated abilities and will have colons in their reminder text.