origin, Japheth is a sickly child, believed to have stomach cancer, enters the desert to kill himself where he is found by Magneto who helps release the slugs from his stomach the first time
off panel
a few years pass, chooses codename Maggott, enters some indentured servitude
Uncanny X-Men (1st series) #345, 347
first appearance, tracking down Joseph
Uncanny X-Men (1st series) #349
attacked by Psylocke, who senses a great darkness within him
Uncanny X-Men (1st series) #350
teleported to Gambit’s trial in Antarctica, mistakes Joseph for Magneto until he learns that the real magneto is present too and secretly masterminds the trial, keeps quiet about it because of their past connection
X-Men (2nd series) #70
helps defend the Xavier’s mansion from an attack by Juggernaut, uses his slugs to devour a bomb that was implanted to Scott Summers‘ stomach, joins the X-Men
X-Men (2nd series) #71-72
comes up with excuses for not eating with the others, flirts with the ladies
X-Men (2nd series) #73
reveals that Joseph is not Magneto when Sabra attacks him
X-Men (2nd series) #74-75
fears his slugs have started killing people, though actually they were influenced by the Ru’tai
X-Men (2nd series) #76
confides in Wolverine
X-Men (2nd series) #79
sent to Massachusetts Academy
Generation X (1st series) #49
aattacked by mercenary Slaughter, leaves Generation X to hunt him down
Weapon X (2nd series) #5
captured by Weapon X agents and taken to mutant concentration camp Neverland, where he dies in a gas chamber
Weapon X (2nd series) #13
surviving slug in a holding tank in Sinister’s lab