I have heard this term being used to describe a particular Pokemon in a person's team. It comes out of the competitive scene, although I don't really get what it means.
For example, a blog post about Flygon on Smogon which describes it like so:
Flygon is a staple on many teams as a scout, revenge killer, and all-around reliable clutch Pokémon.
I don't think the term is necessarily restricted to Pokemon as I can recall hearing it in other games such as Counterstrike and Call of Duty.
What does it mean?
Best Answer
The term "clutch" was originally used in sports commentary, describing a player that can keep their head cool and perform well during a tense moment in a game, where the outcome of the competition was at stake.
Definitions of "clutch" (adjective):
This term has since migrated to competitive gaming, where is used in similar situations, usually in professional gaming events where there is a lot at stake.
A good example of the term is used in a recent IGN article on the International Dota 2 Championships: