(hex:77) is a glitch item in Pokémon Red and Blue. It is an unterminated name glitch item.
As it is an unterminated name glitch item, it has effects associated with those items, and can be used for screen data exploits like LOL glitch, Yami Shop glitch or will usually cause the TMTRAINER effect in battle.
Using this glitch item outside of battle with a 0x50 sub-tile early enough on the screen may cause the game to freeze.
Using this glitch item in battle with the GameShark code 0150A0C3 to place a 0x50 sub-tile earlier on the screen (or possibly OAM DMA hijacking) may cause a different freeze involving a specific E4 35 00 35 pattern saved to unbanked SRAM (SRAM bank 0) and multiple "|'r" tiles being printed on to the screen. Where the "|'r" (or variable character followed by 'r) are appears to be random to an unknown extent.