“Aha!” The professor leaned forward eagerly. “Most simple teleportation spells are designed to transport the caster herself, and as such, the caster is the target of the spell. Of course, there is no reason why anypony else cannot be the target, but such spells are rarely taught or used.  One simple variant is the marked teleport, in which any creature marked immediately before the teleport is triggered is carried along with it.”