Jeanne Wyshak first loaded a picture of the sprouting mushroom to about two weeks ago.
Since then, she's created her own Flickr gallery where you can follow the mushroom's growth curve.
The pictures above show the mushroom at Day 16.
Wyshak sent some of her pics to Steven Pencall of the Los Angeles Mycological Society. He thinks the giant is Dictyocephalos attenuatus.
We just think it's big and are amazed as, is Wyshak, that the mushroom lives on somewhere in Echo Park.
Wyshak won't share its location, for obvious reasons.
"I think the usual destructive kids are out of town on vacation," she wrote in an email. "Otherwise it would have been kicked over long ago."