Gate, PHB p. 244
When you cast this spell, you can speak the name of a specific creature (a pseudonym, title, or nickname doesn’t work). If that creature is on a plane other than the one you are on, the portal opens in the named creature’s immediate vicinity and draws the creature through it to the nearest unoccupied space on your side of the portal.
(Gate has no errata as of the latest PHB errata)
Can a spellcaster name a type of creature (such as "Nalfeshnee", "Fire Elemental", or "Ancient Blue Shadow Dragon") and have a creature of that type appear? Or does the caster need to name a specific individual creature, such as "Tarphon the Devourer"?