What are cool things to shapeshift into?

For my story they all take some mutation pill that was suppose to treat cancer but it was a failed test and it turns you into a animal for a time. theres 3 of them 2 girls 1 guy. I want one of the girl to be a lioness and the other a leopard but then what should they guy be? What ever it is please not a wolf or dragon or mythical creature, also it needs to be able to put with speed and agility and not a cheetah only because i tend to dislike cheetahs. I was thinking a tiger since they so amazing but tigers tend to be very large and bulky right?