A fruit?? A weird insect? A strange slug? AN ALIEN!?
There were some more...
They were on a Quercus robur tree. Have you ever found something like this on oak trees?
I only started learning to look for galls recently, and it's an all-new world of information and relations among species!!
Please do not forget to check the other daily photography initiatives:
Weekday Challenges:
and initiated by 
and initiated by 
...and challenges
: (- Monday: #foodphotography and #animalphotography; - Tuesday: #landscapephotography and #cityscapephotography; - Wednesday: #architecturalphotography and #vehiclephotography; - Thursday: #macrophotography and #colourfulphotography; - Friday: #streetphotography and #portraitphotography; - Saturday: #sportsphotography and #smartphonephotography; - Sunday: #goldenhourphotography and #longexposurephotography.