Detecting creatures

[Inevitability]

I double-checked the source for the situation and it actually is polymorph.

Then the type changes to Humanoid (Human), because "The subject’s creature type and subtype (if any) change to match the new form". Detection methods that solely care about subtype (like anything based in a ranger's favored enemy) would not work.

The orc would still be an orc in important other ways, like qualifying for racial feats and classes - few people on this site believe that changing shape should instantly disqualify you for Headlong Rush or Eye of Gruumsh.