Carniflowers, like the weaker Wimpy Flower, are rooted to the ground and thus unable to move, making them rather non-threatening. They are, however, quick to attack, and have a significant attack range, making them at least somewhat dangerous to players early in the game. Their ability to swallow the player's characters can be particularly frustrating.
Their swallow damage is always 3 damage instances with an extra (possible) initial attack that grabs the target. Swallow damage ranges from 1 to 8 pure damage and cannot be reduced by defenses or even Barrier (if it was granted briefly before being swallowed). Swallow duration lasts 3 seconds and does an average of 4 damage per instance. The initial grab-attack has a 50% chance of actually dealing its damage and can be reduced by defenses.
If the player evades an attack, the dog can still be hit and swallowed behind the player (and vice versa). Their hit % (Stats) is quite high, so the player will rarely evade its attacks.
Carniflowers give very little experience and are not particularly useful for acquiring items and experience. Players looking to acquire money or experience very early on would do better to focus on Skelesnails, Raptors, Frippos, or Widowmakers.