Zir Zeal is a variant of Sir Seal, and is Zombie-type. He has much higher attack and health than the regular Sir Seal, but otherwise has similar stats.
Because he is a Zombie enemy, he has the typical burrowing and respawning abilities of Zombie enemies. However, when Zir Zeal burrows, he takes its sweet time to dig a huge 1500-length tunnel underground, longer than the standing ranges of any cat unit. Consequentially, Zir Zeal tends to overshoot the blindspots of Long-Distance cat units and will actually not pose an immediate threat to your backline.