ERB's step-son, Lee Chase, described the event in an interview with Frank Puncer:  "Mother and Ebbie had evidently been invited to a costume party. I don't think either of them cared all that much for costume parties, but that makes it even more interesting that they went to such great lengths for this one. Several days before the party a rumor spread around the house -- that would be 716 N. Rexford -- that a gorilla had escaped from the zoo. My sister and I were kids and, of course, our curiosity was aroused. 

I recall Ebbie telling us: "That gorilla has been seen in the neighborhood, so you kids watch out!" The servants (we had a butler, chauffeur and cook) were not in on it either. So hints were dropped for several days about this escaped gorilla and everyone was on the lookout. 

Then one day mother said: "Oh my God, look out in the backyard!" We had a rather deep backyard, as they have in Beverly Hills, and way out in he back was this gorilla. I think my heart dropped right into my shoes. My sister and I ran out of the house. The butler ran out with a hatchet that he'd found -- he was going to protect the family.

I looked at mother and she was giggling and laughing. My sister caught on before I did and ran over and jumped in the gorilla's arms. Then Ebbie took off the head of the costume and there he was! He just got the biggest kick out of that. 

Then they went to the party and that's were the photograph was taken. The ape/gorilla suit might have been something he found on a movie set and decided to borrow. The chain, of course, wasn't real; it was made of plastic. Later I figured out that Ebbie really enjoyed that sort of thing."