Echo the Copy Cat
An S-tier support pet. Echo gathers no resources at all — instead it copies your own training. While assigned to a mission slot it banks a percentage of every point of skill XP you earn, and Collect pays that XP straight back into the same skills.
How much it copies
Echo's cut runs from 10% (1★, level 1) to 20% (5★, level 999). Stars and level each contribute half the range, so neither maxes it alone: stars come from shards, and Echo's level is capped by your 
Exploring level.
| Stars | Level 1 | Level 50 | Level 99 |
|---|---|---|---|
| ★ | 10% | 13% | 15% |
| ★★ | 11% | 14% | 16% |
| ★★★ | 13% | 15% | 18% |
| ★★★★ | 14% | 16% | 19% |
| ★★★★★ | 15% | 18% | 20% |
Notes
Echo copies every skill except Pets itself (that would let it accelerate its own skill).
It has no income cap — unlike gathering pets, it only ever pays for training you actually did, so it can't be farmed by idling.
The Beastmasters' Guild Trials (Pets 99) pay the 25 shards that unlock Echo. Once you finish the guild, Echo also drops from the Pet Box at the same odds as every other pet. Its star-ups cost 25 / 50 / 100 / 150 / 250 shards (about 2.5× a standard pet).