Perceived threat:
Tatsu sees Gohan, the strong figure who provides food and shelter, seemingly defeated by a static, lifeless object. The Saiyan's mind, untempered by human nuances, registers the tree as an aggressor.
Primal instinct: An alarm bell blares in Tatsu's mind, driven by his natural, aggressive territorialism. The only form of kinship he knows is the brutal, protective bond of the Saiyan warrior. Seeing his elder, his only source of stability, "downed" by a superior force triggers a ferocious, instantaneous response.
The attack
A savage charge: With a roar that echoes through the hills, Tatsu bursts from the woods. He is not running, but blitzing, a blur of motion fueled by pure, unadulterated fury. The sheer force of his charge sends him crashing against the tree, not simply hitting it, but obliterating it. Wood chips explode outward as the massive trunk splinters and is reduced to rubble.
Energy blast: As the tree falls, Tatsu fires an instinctive, uncontrolled energy blast into the remnants, ensuring the "threat" is completely neutralized. He does not use a named attack or a refined technique, but a raw surge of power born of his fury.
The aftermath and Gohan's cunning
Gohan's perception: Gohan, who had been chuckling at his own dramatic fall, is genuinely startled by the savagery of Tatsu's reaction. He understands, however, the immense value of this act. The boy didn't choose to save him; he did it out of a deep-seated, territorial instinct. This is not human kindness, but something far more primal and, in its own way, just as profound.
Gohan's cleverness: Rather than reprimanding Tatsu for his destructive overreaction, Gohan plays along. He feigns weakness, moaning softly as he leans against Tatsu. He thanks the boy, praising his strength and speed. His gentle words, a stark contrast to the boy's ferocity, are like a soothing balm to Tatsu's inner turmoil.
The unspoken lesson
This is a pivotal moment for Tatsu. He doesn't understand the complex human emotion of gratitude, but he does understand that his ferocity was deemed useful and good by the person he instinctively protects.
This event cements Gohan's position as Tatsu's alpha.
It reinforces Tatsu's belief that his savage, protective nature is the right path, even if it's based on a complete misunderstanding.
It gives Gohan a glimpse into the depths of Tatsu's untamed loyalty and offers a new way to reach him. Gohan now knows that Tatsu's fierce Saiyan instincts are not just a liability, but also a raw, powerful source of a different kind of devotion. He can begin teaching Tatsu how to channel that wildness into something more than just brute-force protection.