9. Abandoned Toad
Of all the members of the Brotherhood of Evil Mutants, no-one was more loyal to Magneto than Toad.
Mortimer Toynbee was born with the ability to jump incredible heights. Unfortunately, his mutation also gave him a frog-like appearance and hunched body that caused him to be severely bullied all through childhood.
When Magneto rescued him from life as an outcast, Toad threw himself at his master's feet and became his sycophantic toady (Stan Lee is nothing if not literal). Magneto though, saw Toad as nothing better than cannon fodder and would constantly heap verbal and physical abuse on him for even the slightest failure.
Things finally came to a head when Magneto and Toad approached the cosmic scientist and Colonel Sanders lookalike known as the Stranger, thinking he was a mutant. Stranger kidnapped them both and took them back to his home planet to study.
The Master of Magnetism was able to escape by using his powers to repair a spaceship on the Stranger's world. However, he also completely abandoned his loyal servant Toad, leaving him to a fate ironically similar to a frog in a classroom.
Later on, he changed his mind and went back for Toad. The damage had been done though and Toad turned against Magneto, abandoning his Brotherhood with Quicksilver and Scarlet Witch.