Heyo everyone, so im going to start off by saying the obvious, which is that im a Morde main, Top and mid, occasionally bot. I need some advice on who to play jungle when i do get autofilled into jg, id go Morde, who sustains easy in the jungle, but i dont think hed really be viable.
Do you have 
? Honestly one of the easiest champs to jungle with. Him and 
.
I'd say it depends on what your team's comp is, if your team has CC already and also could use the magic damage then I'd say go for morde, b/c you can utterly nuke someone if the laners lock them down, easy to get dragons etc.
However, if your team is lacking in CC or initiation I'd go w/ one of the options some of the folks have listed here, is decent because of his great sustain and W blood trails help a lot w/ moving around the map. 
is a great tanky jg and his ult is a major difference maker in mid/late game teamfights, I personally like 
and 
a lot in the jg because you can easily opt into a bruiser build after jg enchant and 1 other damage item and still do great damage, Whereas WW is only going to build Titanic hydra for damage most of the time and Mumu is going full tank.
To sum up in answer to the OP, Morde CAN be viable in the jg, but only in certain teams that already have CC and setup so that he can do reliable damage and stay on targets, but if not there are several fairly simple different types of junglers that can do well for different situations.
Not to encourage it but jungle 
was used in pro play once.
Here are some easy and reliable options for you:
They are all pretty easy to play with little to no skillshots in most cases and have good gank pressure.
