Final answer:
The hollow within Ichigo's mind is named Hichigo. This character is a representation of Ichigo's hollow powers and internal conflict, and plays a crucial role in the development of Ichigo's abilities in the anime 'Bleach'.
Step-by-step explanation:
The name of the hollow within Ichigo's mind in the anime series Bleach is Hichigo. This character is also known as Hollow Ichigo, White Ichigo, or more officially as Zangetsu by Tite Kubo, the series creator, in later arcs.
Throughout the series, Hichigo represents the dark side of Ichigo's soul and is the manifestation of his hollow powers. Hichigo challenges Ichigo for control over his body, claiming that he is the true Zangetsu. Importantly, this inner conflict and character highlights the complexity of Ichigo's powers and his struggle to come to terms with them.