With fetch monsters, does skilldrain cancel their effect? i.e Tomato, Rat, Pyramid Turtle.

No, skill drain only negates the effects of monsters that are face up on the field when their effects activate and resolve. Since tomato, etc. activate in the graveyard, they are out of reach of skill drain

The correct slang term is searchers. The proper term is Graveyard effect. Skill Drain DOES NOT negate the effects that trigger in the Graveyard.

No because the effect activates in the grave therefore its not on the field anymore so its not effected by skill drain anymore.

so, End of Anubis would negate those search monsters, right? I could be wrong.

Yes since that basically what end of the anubis says in his effect what he does.

The End of Anubis will negate effects of most "searchers" since it negates effects that activate in the Graveyard (latest print of the card even specifically says that it negates effects that activate in the Graveyard)