So I’m working and I hear my baby cousin “roar” then go “Boo!”, I turn around to see her trying to scare my old Kreepus Calypso and the old thing acted scared and pretended to faint, kid cousin is now giggling. Is this an okay play? I’m just worried something will happen (my parents have glass coffee tables and won’t get rid of them)

Yes, thats very much okay!

Your Kreepus Calyspo is encouraging the scaring behaviour of your baby cousin very deliberately, and I doubt she would accidentally faint in such a manner where she could break something or injure herself/your baby cousin.

It sounds like good, reciprocal play between the both of them!

Best of luck!