There's way too many options on what you can do with this thing and, frankly, not enough tools to do any of them well. They really left you in the deep end of the pool with no floaties or even a pool ring.

You know this thing isn't going to instantly kill you. They would've shot you in the back of the head if they just wanted you dead. You also don't want to get TOO close to this thing.

Doesn't really help that looking at it makes you feel really, really weird.
Wait! An idea (how rare) manifests inside your grey matter. This might just work.

You exit the containment cell in a hurry. You easily find where you left the bin and cigarette-mold infested broom. The mold has already started to climb up from the bristles up to the cheap plastic handle.
The plastic it touches is already starting to weaken and corrode. It didn't do much to the steel walls and floor but it IS somewhat corrosive, huh? Noted.

You snap the handle easily thanks to the cigarette mold's help. The handle you're left with is long enough that it fit in one, maybe two, of the anomaly's arms. Good enough for you.
You re-enter the containment cell with little to no fanfare. The anomaly didn't notice you were gone at all.

The lights begin to flicker yet again. The hands clasp and grasp futilely, desperately, for anything to grab onto. The light above is starting to make a lot of noises you don't like to hear! Sizzling, crackling, creaking...
The ceiling light is slowly loosening from its frame. Okay, okay, you need to stop this NOW before the anomaly hurts itself.

You gingerly lower it the handle towards one of the anomaly's hands. The hands, you note, aren't rotten in any way. They're slender, pale and pristine. Odd. You wonder where the rotten smell is coming from then.
Two hands weakly grasp the handle.

The other hands begin to slow down. Their grasping, flailing digits are now lifeless. The lights stop flickering and any weird noises you were hearing cease entirely.

IN LIMBO tenderly runs its fingers along the broom handle you gave it. Other hands try to grasp at the broom but there's only so much room its hands can grasp onto.
You count at least four hands all struggling to hold onto it at the same time before it stops trying to add more.

You wonder how strong its grip is but you'll have to test that out later. If a broom handle is enough to keep it placated for now, you're not going to complain.

You lean against one of the containment cell walls. You don't have anything to write with so you might as well commit this to memory. Time to observe the anomaly.
Any movement it makes is slow and subtle. Its hands continue to rub the broom handle that could be described as 'lovingly' if not for. How frankly surreal the gesture is to you.

Its flowers gently sway as if there was wind blowing past them. Without the flickering of dying lights, the containment cell is remarkably quiet. Quiet enough where you can hear your own breathing.

It's peaceful in here.