Cheapest priced copy (Ravnica: Clue Edition): $0.69 at Card Kingdom, near mint, their price list as of .
Scuttling Sentinel 
Creature — Crab Elf · 3/2 · Uncommon · Ravnica: Clue Edition · #42
Flash
Vigilance
When this creature enters, put a +1/+1 counter on another target creature you control. Until end of turn, that creature becomes a blue Crab in addition to its other types and gains hexproof. (It can't be the target of spells or abilities your opponents control.)
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.69 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Ravnica: Clue Edition | 42 | Uncommon | $0.69 | — |
3 rulings from Wizards of the Coast
- 2 February 2024The target creature will not retain its previous colors; it will just be blue until end of turn.
- 2 February 2024The target creature retains any types, subtypes, or supertypes it has.
- 2 February 2024The target creature will become a blue Crab in addition to its other types and will gain hexproof even if counters can't be placed on it for some reason.