There are so many things that are unspecified that make this hard to answer and questionable, but I'll do my best to stay away from that.
Elephant - Doubt it. It won't stand there long enough for you to hack away at it and as we know elephants and be crazy as hell.
Bear - Still a pretty shitty chance, but if it's a cub then go for it.
Pack of lions - lmao
Now this would all be different if I was some bad ass swordsman like Kenshin or the likes of that...
and I like how I'm one of few who took this seriously rofl, but this would be a good way to make the paper.