This spell is normally taught only as a gift from a Spirit Naga. When cast it will summon any nearby serpents and compel them to follow the Mage's commands for Level rounds. The number of serpents that respond to the call (and the time it takes them) varies widely based on location. In the Twilight Jungles a Snake : Swarm is usually summoned, while on the One-River a Snake : Constrictor is more normal. Rarer snakes will be summoned in 5D10 minutes. If the time to appear ends up greater than the Mage's Level + Presence then the serpent abandons the call. If you know that a specific snake exists then the Call always applies to it if possible.