Totem of the Platypus

The Path of the Totem Warrior is a spiritual journey, as the barbarian accepts a spirit animal as guide, protector, and inspiration. In battle, your totem spirit fills you with supernatural might, adding magical fuel to your barbarian rage. Most barbarian tribes consider a totem animal to be kin to a particular clan. In such cases, it is unusual for an individual to have more than one totem animal spirit, though exceptions exist.

Spirit Seeker

Yours is a path that seeks attunement with the natural world, giving you a kinship with beasts. At 3rd level when you adopt this path, you gain the ability to cast the Beast Sense and Speak with Animals spells, but only as rituals.

Totem Spirit

At 3rd level, when you adopt this path, you choose a totem spirit and gain its feature. You must make or acquire a physical totem object that incorporates a part of the totem animal. At your option, you also gain minor physical attributes that are reminiscent of your totem spirit.

Your totem animal might be an animal related to the one listed here but more appropriate to your homeland.

Platypus:  While you're raging, the first creature you hit on each of your turns with a weapon attack takes extra poison damage equal to 1d6 + half your barbarian level.

Aspect of the Beast

At 6th level, you gain a magical benefit based on the totem animal of your choice. You can choose the same animal you selected at 3rd level or a different one.

Platypus:  You can hold your breath for up to 15 minutes at a time. Additionally, while you aren't wearing heavy armor or using a shield, you gain a swim speed equal to your normal speed.

Spirit Walker

At 10th level, you can cast the Commune with Nature spell, but only as a ritual. When you do so, a spiritual version of one of the animals you chose for Totem Spirit or Aspect of the Beast appears to you to convey the information you seek.

Totemic Attunement

At 14th level you gain a magical benefit based on a totem animal of your choice. You can choose the same animal you selected previously or a different one.

Platypus:  While you are raging, your inability to see a creature doesn't impose disadvantage on your attack rolls against it.  You are also aware of the location of any invisible creature within 30 feet of you, provided that the creature isn't hidden from you and you aren't blinded or deafened.