It's not really boring, I suppose, it just add flavor.
What I don't want to happen is...
The critter is ripping through your 8-9th level party 'cause it has DR 15, immunity to spells 8th level and lower and can deal out some serious magic before shredding you with it's well-manicured claws... and you still just think it's a hobgoblin on steroids because of the shape shift ability. Add on that it can read minds, so it should know exactly what your players are saying to one another, even if they were speaking another language or using telepathy. Yeah, it can get ugly in a hurry... and then you finally piece it together: cat fur on all of the bedding, all of the luxurious finery around the place, spell immunity, DR, and get it to reveal itself to you. So you bless a crossbow bolt in hopes of saving the ranger's life in the nick of time...
...when it deflects your shot as if you were an annoying pest and pounces on the cleric before she can scream let alone bless anything else. Then the party manages to back off and fire two blessed bolts at the same time at the thing, one of which is deflected, but the other hits it soundly...
...only to have it laughingly fake it's death to rise up again and devour someone else. After that, it's snack time for the Rakshasa, and you are rolling up your new PCs.
Not good, as it would make quick work of your party, and no one would be happy with the final ending.