No, not a kind of chupacabra, but still quite strange.
At this time of year I have always wondered what all these sticky fluffly bits were on my Box Hedge, and now I finally know.
When you get closer you can see hidden amongst the fluff these Psyllid nymphs which look a little like greenfly. They are called Box Sucker Psylla buxi, and in other parts they are called Boxwood Psyllid. They appear to do little damage to the Box, and they disappear after a while. They are true bugs which suck the sap from the shoot tips in spring.
This is the first time I have seen the little critters up close, and how bizarre they look. They almost look like they have large ears, but I think they are the beginnings of wings.
May 2019, rear garden, Staffordshire, England. © Pete Hillman.