This would be a Safe class SCP. It is a grapevine, that if you talk to the vine and then pick a grape, eating that grape will repeat all words you said, word for word, in a slightly deeper voice. Anyone can eat the grape you talked to, and after picking a grape, new words can be said to the grapevine without the previous message being stored on the grape.
Any ideas?
EDIT: When coming up with a backstory (Probably should have done that first) I came up with a few secondary effects. One of them being that eventually people get driven mad by hearing other people's voices from the grapes, sometimes resulting in suicide. The other being that it absorbs spilled blood into its roots, going so far as to roll uphill towards the vine if necessary.