My opponent has a Nevinyrral, Urborg Tyrant in play, which has hexproof from creatures. I play Gilded Drake to swap control with Nevinyrral. My opponent says that the hexproof from creatures applies to the Gilded Drake. I argued that the Drake is not targeting Nevinyrral but rather that I am targeting Nevinyrral.
For purposes of "hexproof from artifacts, creatures, and enchantments", Gilded Drake's triggered ability targets "up to one ... creature an opponent controls" (C.R. 115.1d), and that ability is an "abilit[y] ... from [a creature] sourc[e]" (C.R. 702.11d; see also C.R. 702.11f). Thus, if you control Gilded Drake and your opponent controls Nevinyrral, that ability can't target Nevinyrral (C.R. 702.11d; see also C.R. 702.11f).
Note, however, that Gilded Drake itself doesn't target anything; with limited exceptions, no permanent spell can have targets (C.R. 115.1b, 115.1e). Thus, you can cast Gilded Drake as normal (review C.R. 601.2, 601.2c).