If you are wanting to tame with the snow owl. You can use the owl’s secondary attack to freeze the owl and use up the stamina. This will force it to eat more and will produce the pellets for taming the gatcha. It also works well once you have it to get higher quality crystal drops from it. Just put the owl in front of the gatcha and then when the owl drops pellets the gatcha will pick it up automatically.
Rare mushrooms add 50 food per. Don't decay. Easy to get from megachelons. Rare flower work as well. Beware they starve extremely fast. So only food with high enough food value will keep them alive. Aka not the seeds u get from megachelons. That will cause them to starve faster than they can eat.