I've been away for a week, but the carcavulp is definitely a fox-like creature rather than a fish
Here is the text from the back of the card:
AD&D 2nd Edition Trading Cards
#606
Carcavulp
Armor Class: 4
THAC0: 15
Movement: 15
Hit Dice: 6 + 3
Alignment: Neutral Good
Size: M (4' tall, 6' long)
Intelligence: Low (5-7)
Combat: #AT 3 + special: Dmg 1-6/1-6/2-26; special attack is a bonus of +4 to attack and damage due to its strength and speed
Description: The carcavulp is a magically created creature combining the best attributes of the fox and wolverine. The creature has enlarged size, giving it greater muscle mass and strength. Carcavulps can be created to recognize a specific master.