The list groups pets by this site's strategy tier, not by hatch rarity. Rarity describes how an item enters the game; tier estimates how consistently its ability helps common garden plans. A rare pet can therefore rank above a harder-to-find pet when its passive is easier to activate or useful in more situations.
Compare role before size
Start with the ability you need: crop mutation support, growth, hatch speed, XP, cooldown help, or general utility. The ability search is faster than scanning names when you already know the job. Once you have two or three candidates, open their detail pages to compare hatch weight, ability notes, and likely place in a team.
Why age and weight need separate checks
Current weight rises with age, so a large displayed number can describe an older pet rather than a better hatch. For trade comparisons, record current age and weight and recover the estimated hatch value with the pet weight calculator. Compare candidates at the same projected age, then consider whether their abilities scale with weight.
What a tier cannot tell you
A tier is not a fixed Sheckle price, a promise of trade demand, or a substitute for the current patch notes. Team composition matters: several individually strong pets may overlap the same role, while a lower-ranked specialist can complete a weather or mutation setup. Use the ranking as a shortlist and verify visible stats in game before trading.