No, definitely no tarantulas. I would say the wildlife was way more abundant in Mexico than I've ever experienced in Jamaica. I really don't like birds to be honest, and we went swimming in the sea and in swooped an enormous pelican and it landed right next to me and was bobbing along, I almost screamed my head off. I've never swum so fast in my entire life!
I'm definitely more cautious about safety in Jamaica than Mexico, although that said we only really go off on our own around Playa Del Carmen which isn't particularly scary. I found that in Jamaica that SOME locals can be very pushy and a bit scary in terms of wanting to sell you things, it can be quite intimidating if you're on your own, and I've never ever experienced anything like that in Mexico.
At that time of year I would definitely be packing the anti frizz hair products and keeping everything lightweight as it can get super humid. Ooo I so want a holiday right now, it sucks living on a student budget haha!