Sphinx

Lair Actions

Source: Monster Manual

On initiative count 20 (losing initiative ties), the sphinx can take a lair action to cause one of the following magical effects; the sphinx can’t use an effect again until it finishes a short or long rest:

• The flow of time is altered such that every creature in the lair must reroll initiative. The sphinx can choose not to reroll.
• The effects of time are altered such that every creature in the lair must succeed on a DC 15 Constitution saving throw or become dice:1d20|noform|noparens|avg (1d20) years older or younger (the sphinx’s choice), but never any younger than 1 year old. A greater restoration spell can restore a creature’s age to normal.
• The flow of time within the lair is altered such that everything within moves up to 10 years forward or backward (sphinx’s choice). Only the sphinx is immediately aware of the time change. A wish spell can return the caster and up to seven other creatures designated by the caster to their normal time.
• The sphinx shifts itself and up to seven other creatures it can see within in its lair to another plane of existence. Once outside its lair, the sphinx can’t use lair actions, but it can return to its lair as a bonus action on its turn, taking up to seven creatures with it.