Is Rookie a tank?

Tank is not one of the game's roles, and Rookie's role icon shows breaker. Every Aniimo fills a single fixed combat role chosen from DPS, break, healing, support or regen, and that role cannot be changed. "Tank" here describes how Rookie plays: it is durable and carries defensive tools. It is not a slot on your team. You can check this yourself. The role icon sits on Rookie's portrait and at the top of its stats panel.

So build around Rookie as a Dark-type breaker that can also take hits. Its Bouncy Sling makes targets it hits take 15% more break damage for 15 seconds. That makes it a good opener for a team that wants to empty an enemy's break shield, the bar beneath its health bar. Once that bar is gone the enemy staggers.

If you want a sturdier front line

Rookie is not the only durable option. Tucken is tanky too and good at absorbing damage, and it summons Hummin minions that charge in alongside it. Turbo protects in a different way. It can grant a shield, and its empowered Cloud Shield gives a shield equal to 50% of maximum HP. Rookie's own defensive tools keep it standing, but its sling is a break tool, so it fits best on a team with other breakers or damage dealers that follow it up.

Not settled: Because there is no tank role, Rookie's label on its stats panel reads breaker. Evolution can change an Aniimo's role on the team, so check the icon again after Rookie evolves.