They're not resistant. They just don't care. The skeletons would attack what's attacking it. Same with the zombies. But creepers only give a shit about us.

They're probably the ones you'll have to look out most for.

[He scans the field outside, looking at what comes skittering through occasionally. Just some sparse zombies, skeletons. Creepers are hard to immediately see, though.]

Over there. By the treeline. There's a creeper. [So he'll know what one looks like.]