Biologically speaking (ie, pedantically using the scientific definition over the common English usage) a Chimera and a Hybrid are quite different things (potentially with interesting consequences).
A hybrid is basically a mix; a cross-breed. You are a hybrid of your parents for example. Usually no net gain in genes is made, so the child has the same number of genes, picked more or less at random from both parents with the remainder being discarded. Occasionally genes get added, very occasionally an extra chromosome will get inserted or all chromosomes will double up.
An additive hybrid might be interesting, eg, the child has the sum of it's parent's (and ancestor's genes) all mixed up. It could also exhibit the most incredible Hybrid Vigour.
Edit Building on @Henry Taylor's comments to User6760's answer. The developmental genetics of this Hybrid would need some extra super-monster oversight, possibly from it's own set of super-monster genes. Developmental Genetics comes into play most when we're still embryos, where genes are turned on and off in a strict order, to make sure (for example) that the inside of your spleen doesn't end up on the outside, or that you have the correct number of heart chambers.
A Chimera is even more fun. Chimeras have 2 distinct genomes making up different parts of their body. The simplest artificial example is a grafted tree, where roots with one genome (bred for disease resistance and vigour) are joined to the stem and leaves of another (bred for tasty tasty fruit). Frankenstein's monster (or a transplant recipient) might be considered an artificial Chimera.
It happens a lot in plants and animals naturally too, usually where 2 fertilised embryos have fused and gone on to grow as a single creature, with different tissues (or even whole organs) being composed of one or other genome.
On Earth now, we see two genomes often, several genomes occasionally. So, what about all the genomes? Well, with a bit of storytelling, why not.