“Who was once a little green slab of clay…Gumby!” If you recall that lyric, You probably grew up watching Gumby and Pokey and all their Plasticine pals. You probably, at one point, also owned a bendable green Gumby figure. Gumby dates back to the Eisenhower era of the mid-’50s. Teletoon Retro celebrates his 60th anniversary Thursday, Jan. 29,