What you found sounds exactly like an Osage orange (also called a “hedge apple” or “horse apple”).
🌳 What it is
- The fruit of the Maclura pomifera
- Bright green, bumpy and brain-like surface
- Often found under trees in late summer or autumn
🤲 Why it feels sticky
- It contains a milky, latex-like sap
- That’s what gives it the slightly sticky texture
⚠️ Is it edible?
- Not poisonous, but generally not eaten
- Very bitter and hard
- Can upset the stomach if consumed
🐿️ Do animals eat it?
- Most animals avoid it
- Squirrels may pick at the seeds inside
🧠 Fun facts
- Historically used as natural fencing (“hedge” trees)
- The wood is extremely strong
- Some people believe the fruit repels insects—but evidence is weak
✅ Bottom line
That strange “brain-like” green ball is just the fruit of the Osage orange tree—unusual-looking, harmless, and very common in certain areas.
If you want, you can describe the tree or send a photo, and I’ll confirm it 100%.