De or het wanschepsel?

The correct Dutch article is:

het wanschepsel

Rule Words ending in -sel: usually het. See the rule

How to use wanschepsel

the wanschepselhet wanschepsel
this wanschepseldit wanschepsel
that wanschepseldat wanschepsel
our wanschepselons wanschepsel
your wanschepseljouw wanschepsel
every wanschepselelk wanschepsel
which wanschepsel?welk wanschepsel?
a big wanschepsel / the big wanschepseleen groot wanschepsel, het grote wanschepsel