Based on the examine text and the message when eaten, it is likely that mystery meat is in fact human meat.

{"type":"scatter","options":{"tooltips":{"intersect":false,"format":"skillingSuccess"},"datasetsPerGroup":3,"aspectRatio":1.35,"title":{"display":true,"font":{"size":18},"text":"Mystery meat cooking chance","position":"top"},"scales":{"y":{"ticks":{"stepSize":0.1,"format":"percent"},"scaleLabel":{"display":true,"labelString":"Success rate"}},"x":{"ticks":{"stepSize":1},"scaleLabel":{"display":true,"labelString":"Level"}}},"maintainAspectRatio":false,"fill":false},"minWidth":"540px","resizable":true,"width":"540px","isChartObj":true,"height":"400px","isFinished":true,"minHeight":"400px","data":{"datasets":[{"fill":false,"borderCapStyle":"round","label":"Normal ","showLine":true,"data":[{"y":0.50390625,"x":1}],"pointStyleImg":"Cooked mystery meat.png","hoverBackgroundColor":"rgba(151,198,222,0.5)","backgroundColor":"rgba(166,206,227,0.3)","borderDash":[5,5],"borderColor":"rgba(166,206,227,1)","hoverBorderColor":"rgba(151,198,222,1)","pointRadius":0,"clip":5,"baseColor":"gray"},{"pointRadius":0,"label":"Normal ","showLine":true,"data":[{"y":0.50390625,"x":1},{"y":0.515625,"x":2},{"y":0.53125,"x":3},{"y":0.546875,"x":4},{"y":0.55859375,"x":5},{"y":0.578125,"x":6},{"y":0.59375,"x":7},{"y":0.60546875,"x":8},{"y":0.62109375,"x":9},{"y":0.640625,"x":10},{"y":0.65234375,"x":11},{"y":0.66796875,"x":12},{"y":0.68359375,"x":13},{"y":0.69921875,"x":14},{"y":0.71484375,"x":15},{"y":0.73046875,"x":16},{"y":0.74609375,"x":17},{"y":0.7578125,"x":18},{"y":0.77734375,"x":19},{"y":0.79296875,"x":20},{"y":0.8046875,"x":21},{"y":0.8203125,"x":22},{"y":0.8359375,"x":23},{"y":0.8515625,"x":24},{"y":0.8671875,"x":25},{"y":0.8828125,"x":26},{"y":0.8984375,"x":27},{"y":0.9140625,"x":28},{"y":0.9296875,"x":29},{"y":0.9453125,"x":30},{"y":0.95703125,"x":31},{"y":0.97265625,"x":32},{"y":0.9921875,"x":33},{"y":1,"x":34}],"fill":false,"hoverBackgroundColor":"rgba(29,114,171,0.5)","backgroundColor":"rgba(31,120,180,0.3)","borderDash":[],"borderColor":"rgba(31,120,180,1)","hoverBorderColor":"rgba(29,114,171,1)","borderCapStyle":"round","clip":5,"baseColor":"gray"},{"borderCapStyle":"round","hoverBorderColor":"rgba(169,219,124,1)","showLine":true,"data":[{"y":1,"x":34}],"fill":false,"hoverBackgroundColor":"rgba(169,219,124,0.5)","borderDash":[],"borderColor":"rgba(178,223,138,1)","backgroundColor":"rgba(178,223,138,0.3)","pointRadius":5,"clip":5,"baseColor":"gray"},{"fill":false,"borderCapStyle":"round","label":"Lumbridge range ","showLine":true,"data":[{"y":0.54296875,"x":1}],"pointStyleImg":"Lumbridge Teleport.png","hoverBackgroundColor":"rgba(48,152,42,0.5)","backgroundColor":"rgba(51,160,44,0.3)","borderDash":[5,5],"borderColor":"rgba(51,160,44,1)","hoverBorderColor":"rgba(48,152,42,1)","pointRadius":0,"clip":5,"baseColor":"green"},{"pointRadius":0,"label":"Lumbridge range ","showLine":true,"data":[{"y":0.54296875,"x":1},{"y":0.5546875,"x":2},{"y":0.5703125,"x":3},{"y":0.5859375,"x":4},{"y":0.6015625,"x":5},{"y":0.6171875,"x":6},{"y":0.6328125,"x":7},{"y":0.65234375,"x":8},{"y":0.6640625,"x":9},{"y":0.6796875,"x":10},{"y":0.6953125,"x":11},{"y":0.7109375,"x":12},{"y":0.73046875,"x":13},{"y":0.7421875,"x":14},{"y":0.76171875,"x":15},{"y":0.7734375,"x":16},{"y":0.7890625,"x":17},{"y":0.80859375,"x":18},{"y":0.8203125,"x":19},{"y":0.83984375,"x":20},{"y":0.8515625,"x":21},{"y":0.87109375,"x":22},{"y":0.88671875,"x":23},{"y":0.8984375,"x":24},{"y":0.91796875,"x":25},{"y":0.9296875,"x":26},{"y":0.94921875,"x":27},{"y":0.9609375,"x":28},{"y":0.98046875,"x":29},{"y":0.99609375,"x":30},{"y":1,"x":31}],"fill":false,"hoverBackgroundColor":"rgba(250,135,134,0.5)","backgroundColor":"rgba(251,154,153,0.3)","borderDash":[],"borderColor":"rgba(251,154,153,1)","hoverBorderColor":"rgba(250,135,134,1)","borderCapStyle":"round","clip":5,"baseColor":"green"},{"borderCapStyle":"round","hoverBorderColor":"rgba(216,25,27,1)","showLine":true,"data":[{"y":1,"x":31}],"fill":false,"hoverBackgroundColor":"rgba(216,25,27,0.5)","borderDash":[],"borderColor":"rgba(227,26,28,1)","backgroundColor":"rgba(227,26,28,0.3)","pointRadius":5,"clip":5,"baseColor":"green"},{"fill":false,"borderCapStyle":"round","label":"Hosidius +5% ","showLine":true,"data":[{"y":0.55078125,"x":1}],"pointStyleImg":"Cooked mystery meat.png","hoverBackgroundColor":"rgba(253,183,93,0.5)","backgroundColor":"rgba(253,191,111,0.3)","borderDash":[5,5],"borderColor":"rgba(253,191,111,1)","hoverBorderColor":"rgba(253,183,93,1)","pointRadius":0,"clip":5,"baseColor":"red"},{"pointRadius":0,"label":"Hosidius +5% ","showLine":true,"data":[{"y":0.55078125,"x":1},{"y":0.5625,"x":2},{"y":0.578125,"x":3},{"y":0.59375,"x":4},{"y":0.609375,"x":5},{"y":0.62109375,"x":6},{"y":0.640625,"x":7},{"y":0.65625,"x":8},{"y":0.66796875,"x":9},{"y":0.6875,"x":10},{"y":0.69921875,"x":11},{"y":0.71484375,"x":12},{"y":0.73046875,"x":13},{"y":0.74609375,"x":14},{"y":0.76171875,"x":15},{"y":0.77734375,"x":16},{"y":0.79296875,"x":17},{"y":0.8046875,"x":18},{"y":0.82421875,"x":19},{"y":0.8359375,"x":20},{"y":0.8515625,"x":21},{"y":0.87109375,"x":22},{"y":0.8828125,"x":23},{"y":0.8984375,"x":24},{"y":0.9140625,"x":25},{"y":0.9296875,"x":26},{"y":0.9453125,"x":27},{"y":0.9609375,"x":28},{"y":0.9765625,"x":29},{"y":0.9921875,"x":30},{"y":1,"x":31}],"fill":false,"hoverBackgroundColor":"rgba(242,121,0,0.5)","backgroundColor":"rgba(255,127,0,0.3)","borderDash":[],"borderColor":"rgba(255,127,0,1)","hoverBorderColor":"rgba(242,121,0,1)","borderCapStyle":"round","clip":5,"baseColor":"red"},{"borderCapStyle":"round","hoverBorderColor":"rgba(193,165,207,1)","showLine":true,"data":[{"y":1,"x":31}],"fill":false,"hoverBackgroundColor":"rgba(193,165,207,0.5)","borderDash":[],"borderColor":"rgba(202,178,214,1)","backgroundColor":"rgba(202,178,214,0.3)","pointRadius":5,"clip":5,"baseColor":"red"},{"fill":false,"borderCapStyle":"round","label":"Hosidius +10% ","showLine":true,"data":[{"y":0.6015625,"x":1},{"y":0.61328125,"x":2},{"y":0.625,"x":3},{"y":0.64453125,"x":4},{"y":0.65625,"x":5},{"y":0.67578125,"x":6},{"y":0.6875,"x":7},{"y":0.70703125,"x":8},{"y":0.71875,"x":9},{"y":0.734375,"x":10},{"y":0.75,"x":11},{"y":0.765625,"x":12},{"y":0.78125,"x":13},{"y":0.796875,"x":14},{"y":0.8125,"x":15},{"y":0.828125,"x":16},{"y":0.84375,"x":17},{"y":0.859375,"x":18},{"y":0.87109375,"x":19},{"y":0.890625,"x":20},{"y":0.90234375,"x":21},{"y":0.921875,"x":22},{"y":0.93359375,"x":23},{"y":0.953125,"x":24},{"y":0.96484375,"x":25},{"y":0.9765625,"x":26},{"y":0.99609375,"x":27},{"y":1,"x":28}],"pointStyleImg":"Cooked mystery meat.png","hoverBackgroundColor":"rgba(101,58,146,0.5)","backgroundColor":"rgba(106,61,154,0.3)","borderDash":[5,5],"borderColor":"rgba(106,61,154,1)","hoverBorderColor":"rgba(101,58,146,1)","pointRadius":0,"clip":5,"baseColor":"blue"},{"pointRadius":0,"label":"Hosidius +10% ","showLine":true,"data":[],"fill":false,"hoverBackgroundColor":"rgba(210,237,146,0.5)","backgroundColor":"rgba(217,240,163,0.3)","borderDash":[],"borderColor":"rgba(217,240,163,1)","hoverBorderColor":"rgba(210,237,146,1)","borderCapStyle":"round","clip":5,"baseColor":"blue"},{"borderCapStyle":"round","hoverBorderColor":"rgba(163,217,128,1)","showLine":true,"data":[{"y":1,"x":28}],"fill":false,"hoverBackgroundColor":"rgba(163,217,128,0.5)","borderDash":[],"borderColor":"rgba(173,221,142,1)","backgroundColor":"rgba(173,221,142,0.3)","pointRadius":5,"clip":5,"baseColor":"blue"}]}}