Some creature or creatures regularly (sunrise and sunset, summer and winter, lunar phases) or irregularly (solar and lunar eclipses, eschatological events) attack the luminaries or shade their light
An (animal) person saves a dangerous animal from a snare or the like. The saved one is going to kill his savior but the third person saves the second (usually tricks the first one to captivity again)
Dangerous animal seeks to kill a person or other animal who rescued it from captivity. The dangerous animal and its victim agree to ask somebody else if a good deed should be repayed with a bad one. Inanimate objects are among those who answer to this question
The duiker (mouse-deer) wins thanks to his smartness
Being smart and witty, a small ungulate overcomes strong adversaries. The hero is a duiker, a mouse-deer or other small even-toed ungulates that are not very close biologically but look similar. In some publications on African folklore it is difficult to say what species is meant in particular case