The King of Evil Trident appears as a giant Trident wielded by Ganon in Ganon's Fury Challenge Mode during his Boss Weak Point Smash and his Focus Spirit Attack. It also appears as Ganondorf's Level 2 weapon in his Trident moveset. While a normal sized Trident when wielded by Ganondorf, it size apparently changes with its master as it is much larger when wielded by Ganon and can be summon via magic.
The King of Evil Trident design is largely based on the Trident wielded by Yuga-Ganon in The Legend of Zelda: A Link Between Worlds. In the game, it is implied that the Trident originally belonged to Ganon and fell into Yuga's possession after he took over Ganon's body to obtain Hyrule's Triforce of Power. Its design resembles the Trident used by Ganon in A Link to the Past differing only in color and minor differences in design.
Given their similar design, it is possible is that it is the same Trident as the one wielded by Ganon in A Link to the Past. Minor differences such as color could be explained away as due to graphical differences between the two titles. Another possibility is that Yuga used his power to alter its color and design slightly to suit his taste in aesthetics, which is likely considering his personality.