Wyrmspan · Board game rules
Does second hatchling ability trigger twice if I put two resources on it in one action?
Quick answer
Yes — the hatchling's second ability triggers separately each time you cache the specified resource or tuck a card, even if both happen during the same action.
Details
Hatchlings have a 3-part ability: an "if activated" ability that lets you cache a resource or tuck a card, a second ability that grants a benefit "any time you cache the specified resource... or tuck a card... on that hatchling," and a one-time bonus on the 3rd cache/tuck [p.9 — Hatchlings]. The second ability explicitly states it triggers "regardless of whether the cache or tuck ability came from walking your adventurer onto that card or from another ability" [p.9 — Hatchlings].
The rulebook also clarifies that when an ability allows you to perform an exchange or action multiple times, "resolve each exchange or action individually," meaning each instance is treated as its own trigger [p.11 — Additional Rules, Notes, and Concepts]. So if a single action lets you cache 2 resources onto the hatchling, you resolve each caching separately, triggering the second ability twice.
Watch out: If the second caching happens to be the hatchling's 3rd overall cache/tuck, you'll also gain the one-time "grown up" bonus at that moment, on top of the regular benefit triggering twice [p.9 — Hatchlings].