You could loosely stack Brick, Round 1 x 1 Open Stud around a core Hose, Rigid 3mm D.. As long as the stack is loose, you should be able to bend the trunk to your desired shape.

I’ll edit in some reference photos later today.

You could loosely stack Brick, Round 1 x 1 Open Stud around a core Hose, Rigid 3mm D.. As long as the stack is loose, you should be able to bend the trunk to your desired shape.

As a bonus, you get the segmented look of the trunk for free. A reference photo:

Or if your scale is smaller, maybe consider Hose, Ribbed 7mm D..