Thinking of Vilix'pran's budding, I always picture sacks on his back developing for where his offspring will gestate until they "hatch". Seeing as how the exact number of how many children they will have is unknown (though seems to get larger with every fertility cycle) I surmise that multiple embryos can form in each "bud", so the parent may start with two buds and give birth to three offspring, next time they have three buds and eight children, etc.
As for what they look like, I imagine something similar to a bat/Anurognathus (sort of like the Gaoul from Titan A.E.), but that's just what springs to my mind.