Typically the phrasing I see people use are:
The all gene animal
The jackpot
The jewel
The star
Or if it was me ... "My holdback"
Although the all genes in my clutches this year will be interesting to see or absolutely impossible to see with BEL complexes involved. Lol
The phrase "hitting the odds" may apply in this circumstance. Breeders say that when it is a long shot, or harder to produce a certain combo, but I would imagine that in some cases this may also apply to what you are referencing here.