The only documented rarity path is another hatch
The official line is to hatch rarer and faster fish so you can find rarer eggs. No second source of fish is documented. No action in reviewed play is shown to raise the odds of one specific hatch. What you can improve is whether you can reach an egg and return before it breaks.
Observed hatches run from a Common Mackerel to an Uncommon Grouper from a Tidal Egg. That range is evidence the loop can vary. It is not a drop table.
Reach, Luck, and labels are different things
Far eggs have shown large luck labels, including about 3M and 30M. A 30M-luck egg expired with about 5 seconds left because the mount was too slow. A faster fish makes that trip possible. It does not, on current evidence, change the hatch.
A Luck stat is visible in play. Players talk about maxing it before a hatch and cite values such as 416 and 1,290. One rebirth was said to reset Luck from about 2,000 to 1. The stat exists in those sessions. What it changes was not shown, and no rebirth tier list, cost, or retained-item rule was recorded. Do not build a reset plan from that one reset.
| Thing players try | What was actually seen | What is not established |
|---|---|---|
| Chase a high luck label | Bigger numbers sat farther out | That the label predicts the hatch |
| Raise Luck | Values such as 416 and 1,290; one reset toward 1 | Any change to hatch odds |
| Buy a radar | It can point at an egg | A range or an odds bonus |
| Feed | Named EXP gains | A required food, or a speed rule |
| Ride a faster fish | Far eggs become deliverable | A change to spawns or hatches |
| Dive deeper | Some water is restricted | A deeper-water drop rate |
Compare two fish without a fake tier list
Speed readouts are real and inconsistent. One player called 200 slow, 3,900 fast, and 190,000 "fast, but not that different." Another session's best fish was 566. In one video a fish labeled around 190 seemed to outswim one labeled 95,000. All twelve Index fish stay unranked. There is no verified fastest species.
Time your own rides:
- Pick one circuit with the same start and finish.
- Ride fish A and record seconds. Note weather, whether you are carrying an egg, and any crash.
- Unequip and mount fish B only. Keep the route.
- Repeat. Prefer a result you can reproduce.
Percent time saved on your route is (baseline seconds minus new seconds) divided by baseline seconds, times 100. That is your measurement, not an in-game stat. If weather, a mutation notice, or the carried egg changed, the runs are not the same test.
Panel numbers that do not measure that ride: occupancy, EXP, weight, Coins/s, Index "1 in" labels, and Equip Best.