I remember when I first moved to France seeing lots of trees with huge bird nests in the topmost branches. Then I realised that they were enormous clumps of mistletoe.
At the top of my garden there is a small tree that has a clump growing low enough for me to examine (and photograph). I don’t know why I find it fascinating but I remember, in the U.K., seeing dried up, tired sprigs of mistletoe for sale at Christmas so seeing it growing and looking so fresh is great although, of course, I know it’s a parasite so I don’t suppose the tree is as happy. Nice to have my own, private supply for hanging over the door though!