Because Eclipse had now become bigger. Previously, in his fox form, he was only as large as a Siberian husky. Now, he was the size of the largest lion in the jungle. Additionally, his tails had increased from six to seven.
This transformation occurred because Eclipse underwent another 'evolution' last week. He didn't witness it firsthand, as he was prohibited from logging into Arcadia for a week due to the college entrance exam. Despite his attempts to convince his father and brothers that logging in for a few hours wouldn't impact his study time, they remained adamant. Shen Ji Yun also shared their opinion, which didn't really help. In fact, it only made the situation worse.