The wildebeest was strongly back-lit, so exposure was tricky. I took the picture with a Canon EOS 7D Mark II, with a Canon EF 100-400 mm f4.5 - 5.6L IS II LSM lens, with a Canon 1.4X III teleconverter. I was shooting at the absolute maximum 560 mm focal length, F8, 1/800 shutter speed and 400 ISO.
Mara River, Serengeti National Park, Tanzania, early November, 2018. November is a little late in the year for the major wildebeest river crossings, but the weather is ideal for photography, and you still have the opportunity for late season crossings. The Mara river is full of immensely large Nile Crocodiles up to 6 meters in length. They have no problem grabbing a full grown bull wildebeest, which can weigh up to 750 pounds, around the midsection. In this image, it's an instant before the lunge. As it turned out, the wildebeest was able to fight free and escape. It suffered some pretty bad puncture wounds from the crocodile's teeth, but unless another predator took advantage later, hopefully, it lived to try to cross the river again on another day.