Can be caught anytime
Can be caught anytime but has special requirements
Can be caught during the day (06:00 - 17:59)
Can be caught during the night (00:00 - 05:59 and 18:00 - 23:59)
Can be caught during the witching hour (00:00 - 00:59)

You can catch event specific pets even during special events
Some events may be inaccurate because there is no set date
You can click on the icon of the pet to hide it
Hover over the pet name to display requirements to catch it