Rare Chu Jelly (gold and sparkles) can be found in quite a few places, such as the Snowpeak area. This Chu Jelly is great because it restores all your hearts and temporarily increases your attack power.
This jelly is rare and thus only shows up in a few locations, such as on the overhang of rocks near the bridge of the Lanayru province. It also only appears once in a while. If you spot it but fail to get it because it combined with another Chu, don’t bother leaving and returning since the Rare Chu will not reappear.