During a recent Game Night: Free For All game I played, the Boundless Elves player tried to cast a Thorn Lieutenant and the Glorious Combat player countered it with Counterspell.
The Thorn Lieutenant card says:
Whenever Thorn Lieutenant becomes the target of a spell or ability an opponent controls, create a 1/1 green Elf Warrior creature token.
Does the casting of the Thorn Lieutenant getting countered count as the Thorn Lieutenant becoming the target of a spell and trigger the creation of a 1/1 green Elf Warrior?
(We assumed not, and reasoned that the counterspell was actually targeting the creature spell that creates the Thorn Lieutenant and that this does not amount to targeting the Thorn Lieutenant himself, but we weren't certain if this was correct, nor how we would determine what the official rule on this is.)