You pour the water down into the Deathclaw's throat. You see it sway its tail in delight slowly side-to-side as the cool liquid funnels down its gullet, finally wetting its parched lips and sore, dry tongue.
If you try to stop pouring the Deathclaw would just grab your arms and force you to keep letting it drink until it's done. When it is finally done, the Deathclaw nibbles at the rim of the canteen, rumbling softly in annoyance as it can't drink anything else.
Now its eyes turn on you.
