Cheapest priced copy (Ixalan): $0.35 at Card Kingdom, near mint, their price list as of .
Kumena's Speaker 
Creature — Merfolk Shaman · 1/1 · Uncommon · Ixalan · #196
This creature gets +1/+1 as long as you control another Merfolk or an Island.
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
1 printing · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ixalan | 196 | Uncommon | $0.35 | $0.49 |
3 rulings from Wizards of the Coast
- 29 September 2017Because damage remains marked on a creature until it’s removed as the turn ends, the damage Kumena’s Speaker takes during combat may become lethal if you no longer control a Merfolk or Island later in the turn.
- 29 September 2017Most nonbasic lands that produce blue mana aren’t Islands. For example, Glacial Fortress isn’t an Island. Some nonbasic lands (such as Irrigated Farmland from the Amonkhet set) do have basic land types printed on the type line and may be Islands.
- 29 September 2017Kumena’s Speaker gets only +1/+1 from its ability, no matter how many Merfolk and Islands you control.