Yeah, specifically for wolves with stars, you'll only find them at night. Daytime only allows ones to spawn without stars. Since not all mountains spawn in the same, I recommend trying to find tiny mountains or any mountain area without too much elevation changes. You want large flat-ish open areas to get good spawn rates and make finding them easy.

Just be sure to have some obstacles or something to keep you safe. Them star wolves are dangerous since their attack speed is so high.