[RPG] How strong is the tressym in comparison to other familiar options?


I was looking at the tressym's description in the Storm King's Thunder adventure, and saw this (p. 243):

With the DM's permission, a person who casts the find familiar spell can choose to conjure a tressym instead of a normal cat.

The tressym seems really strong in comparison to other familiars, such as the owl (who many see as the strongest familiar).

Tressym as compared to the owl:
\text{} & \text{Tressym} & \text{Owl} \\
\text{Stats} & \text{-4, +2, 0, 0, +1, +1} & \text{-4, +1, -1, -4, +1, -2} \\
\text{Skills} & \text{perception +5, stealth +4} & \text{perception +3, stealth +3} \\
\text{HP} & \text{HP(5)} & \text{HP(1)} \\
\text{AC} & \text{AC(12)} & \text{AC(11)} \\

The owl has a flying speed, but it has has almost no ground / climbing speed.
The tressym has the Detect Invisibility trait (with a range of 60 feet) as well as immunity to and detection of poison. These features compared to the Flyby ability of a owl seem not worth it to me.

Is it actually as strong as I think, or am I overlooking something?

Best Answer

It depends on what you're using the familiar for.

Offense: If the familiar is being used as a method to harass opponents to gain advantage, Owl is the winner - it has a superior Fly speed (60' to the Tressym's 40') and Flyby. It can swoop in, take the Help action and get out without provoking an attack of opportunity.

Defense: If the familiar is being used to protect the caster, the Tressym is far superior - it can detect invisibility and poison. Yes, the Owl has darkvision out to 120 feet, but that's only really good for the caster when they're directly using the owl's senses. A Tressym is also intelligent - it can't speak, but that doesn't mean it can't communicate the things it sees.

Companionship: Even when enhanced by find familiar, the owl is still of animal intelligence (Int 2). The Tressym is as smart as most adventurers (Int 11, smarter than some, actually). It can't speak, but it can understand Common. The Tressym is a creature that can actually be a friend; an owl familiar is just a magical tool.