Leave your hotel in Arusha after breakfast and drive to Lake Manyara national park with picnic lunch. Enter the park in the early afternoon for game drives until late in the evening then drive to the lodge/campsite for dinner and overnight. Common animals likely to see at Lake Manyara national park are hippos, tree climbing lions, elephants, giraffes, buffalo, different species of water birds including the lesser/greater flamingos, pelicans, storks etc on the lake.
After breakfast drive to Ngorongoro crater with picnic lunch. After you enter the conservation area descend the 600m high crater wall to the floor of the crater which supports over 25000 wild animals and majority are residents as there is enough pasture and water all year round for game drives until late evening. Ascend the crater and drive back to Moshi/Arusha or to the airport. Common animals found on the crater are black rhinos, jackals, lions and many species of birds like ostrich, kori bustard which is the heaviest flying bird, lesser/greater flamingoes found on the seasonal lake, larks which are the smallest flying birds and many more.