Sped-Up (5e Template)
From D&D Wiki
A sped-up creature is a creature that is far faster than it has any right to be. Presumably, magic which meddles with the flow of time is to blame. Their sheer speed makes them difficult targets and deadly opponents.
Any creature possessing a movement speed greater than 0 feet.
Abilities. Increase the sped-up creature's Dexterity score by 4, to a maximum of 24, unless the base creature already had a Dexterity score of 24 or higher.
Armor Class. Increase the sped-up creature's AC by 2.
Speed. The sped-up creature's speed is doubled. If it has more than one form of movement, all of its movement speeds are doubled.
Evasion. The sped-up creature can nimbly dodge out of the way of certain area effects, such as a red dragon's fiery breath or an ice storm spell. Whenever the creature is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.
Multiattack. If the base creature does not have Multiattack, the sped-up creature may make two attacks. If the base creature has Multiattack, the sped-up creature may make one additional attack.
Recalculate the creature's CR with the following considerations:
- Increase AC by 2.
- Increase damage per round by the effective damage of the multiattack trait.