Nothing is as it should and everything is like it is
It looks like all the other growths around, but if you look away it moves. Changes form and position, next time you look at it you get suspicious. Something is wrong. A plant can´t just move theres branches or walk away! But it moves again. With larger motions.
You cant deny it now, you really saw it.
You are scared but yet you want too stay and feel it, get closer to it. To get another proof that it actually moved. If it moves now you can´t have imagined it. Should you run och stay? Maybe you have found a new kind of creature, a new friend.
Before you could decide, the creature thought one step before and swallowed you.