Generator Servant
Creature — Elemental
, Sacrifice this creature: Add 
. If any of that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and as soon as it comes under your control.)
2/1
Illustrated by
The List#M15-143CommonEnglishLegality
Rulings
Dec 7, 2018
If a creature spell has generic mana only in its alternative or additional cost, the creature will still gain haste.
Dec 7, 2018
If the mana is spent on two different creature spells, each of those spells (and resulting creatures) will gain haste until end of turn.
Dec 7, 2018
An instant or sorcery spell is not a creature spell, even if that spell creates creature tokens.
Dec 7, 2018
If the mana is spent on a noncreature spell that becomes a creature later in the turn, that creature won’t have haste.